Where did the ingredients in that sandwich come from? Our global nutrient tracker tells a complex story

by Nick William Smith, Andrew John Fletcher and Warren McNabb, The Conversation

Where did the ingredients in that sandwich come from? Our global nutrient tracker tells a complex story
Vitamin B12 trade by country income classification, 1986-2020: H = high-income countries, UM = upper middle-income , LM = lower middle-income, L = low-income, ODU = origin or destination not recorded. Credit: Nick William Smith, CC BY-SA

Have you ever looked down at your breakfast, lunch or dinner and considered where the ingredients traveled from to reach your plate?

A basic sandwich in New Zealand can easily represent five countries: an Australian wheat and Indian sesame seed roll, Danish salami, local lettuce and cheese, seasoned with Vietnamese pepper.

And because your food travels a long way to reach you, so does your nutrition.

Research on global food trade—particularly trade in cereals—has a long history. More recently, researchers have begun considering the nutrients—energy, protein, vitamins, minerals—that move around the world within traded food.

As we learn more about the global trade in nutrients we can build a better picture of how these key dietary ingredients are distributed, and how they affect global population health.

Mapping global nutrient trade

The Sustainable Nutrition Initiative undertakes modeling research on the links between global food production and the nutrition of the global population.

Working with researchers at the University of São Paulo and State University of Campinas in Brazil, we have now published a broader analysis of global nutrient trade over time and its impact on health.

It shows the variation in nutrient trade between countries with differing wealth, and some positive links between nutrient trade and health.

Our team built a large data set of all flows of food for human consumption between 254 countries from 1986 to 2020. From this, we worked out the flows of 48 essential nutrients over that period.

As this is too much information for a single scientific paper, the team built an interactive app to let anyone explore the data.

The paper itself focused on a few key nutrients: protein, calcium, iron and vitamins A and B12. These are often used in analyses of food security (having reliable access to enough affordable, nutritious food) because of their importance to human health.

Some of these nutrients are under-supplied in many parts of the world, particularly low-income countries. At the same time, nutrient trade over the 35 years we analyzed has grown rapidly, as shown in the chart below for vitamin B12.

Where did the ingredients in that sandwich come from? Our global nutrient tracker tells a complex story
New Zealand protein exports by country and food group. Credit: Nick William Smith, CC BY-SA

The wealth and nutrient gap

High-income countries were the biggest importers of vitamin B12, but also the other nutrients analyzed, largely from trade with other high-income countries. This is despite those countries having only around 15% of the global population.

In contrast, low-income countries have little involvement in global trade of any nutrients. This limits their ability to improve dietary diversity and quality through food from outside their borders.

Most of New Zealand’s trading partners are in the higher-income brackets. Milk and meat dominate New Zealand protein exports, with China the major partner (see chart below).

The quantity of protein exported would meet the needs of nearly seven times New Zealand’s own population. In a country like China, of course, this is only a small fraction of the population.

In contrast, nearly 60% of New Zealand’s protein imports comes from Australia, largely in wheat and wheat products. And New Zealand imports enough protein to meet around half its population’s need.

We also analyzed the socioeconomic, demographic and health outcome data potentially associated with food consumption patterns and nutrient trade.

The findings suggest higher involvement in nutrient trade networks was significantly associated with improvements in infant mortality rates, lower prevalence of anemia in women of reproductive age, and greater life expectancy.

Food security and nutrition

It is concerning to see the low involvement of low-income countries in nutrient trade, particularly given the benefits it can bring for population health.

Our research provides context for how important traded nutrients are in meeting national population requirements. This knowledge can be used to identify weaknesses in the global food system, and which shocks (climatic, political or biological) might have the greatest consequences for nutrition.

These data can then be combined with other knowledge and modeling of food production, distribution and consumption at national levels to give a more complete view of food systems.

Food trade plays a key role in fostering food security and good nutrition. The trade has grown rapidly in both quantity and economic value over the past 35 years. Understanding its importance for healthy nutrition is essential.

Researchers develop biomimetic-photo-coupled catalysis for H₂O₂ production

by Liu Jia, Chinese Academy of Sciences

Researchers develop biomimetic-photo-coupled catalysis for H2O2 production
The proposed mechanism for the H2O2 production by PEI-GCN/Au biomimetic-photo-coupled catalysis. Credit: Zhang Huiru

A research group led by Prof. Wan Yinhua from the Institute of Process Engineering of the Chinese Academy of Sciences has developed a catalyst with dual photocatalytic and biomimetic catalytic activity for the production of hydrogen peroxide (H2O2).

The strategy involves loading gold nanoparticles (AuNPs) onto graphite carbon nitride (GCN) nanosheets using polyethyleneimine (PEI) as a “bridge.” The study was published in the Chemical Engineering Journal.

H2O2, recognized as an environmentally friendly oxidant, is extensively used in various fields such as medical treatment, environmental restoration, fine chemicals, and electronics industries. However, the conventional method of H2O2 production relies on the anthraquinone process, which has several drawbacks including high energy consumption, the use of organic solvents, and safety hazards. Therefore, there is a pressing need to develop a sustainable and eco-friendly manufacturing process for H2O2.

Solar-driven photocatalysis is a promising alternative strategy for H2O2 production, and GCN is a popular choice in the field of photocatalysis due to its straightforward synthesis, cost-effectiveness, stable physical and chemical properties, and broad light absorption spectrum. However, GCN nanosheets alone have limited performance in photocatalytic H2O2 production in pure water due to the high energy barrier of water dissociation and low separation efficiency of charge carriers.

Hole sacrificial agents (acting as electron donors) such as ethanol, isopropanol, and benzyl alcohol are commonly used to improve the selectivity of oxygen reduction. However, the addition of organic agents has adverse environmental impacts, which is not conducive to the sustainability of H2O2 production. Therefore, it is crucial to engineer a GCN material with enhanced electron-hole pair separation efficiency to facilitate water oxidation and oxygen reduction.

“Inspired by photo-enzyme-coupled catalytic system in chloroplasts, we developed a composite catalyst by loading AuNPs (enzyme mimics) on GCN (photocatalyst) nanosheets using PEI as the ‘bridge’ (PEI-GCN/Au),” Prof. Wan said.

The introduction of PEI and AuNPs helps adjust the electronic structure of GCN, facilitating the rapid separation of photogenerated carriers. The surface plasmon resonance of AuNPs, when excited by incident light, promotes the activation of glucose molecules, elevating their reactivity with O2 and improving the glucose oxidase-mimicking catalytic production of H2O2. The grafting of PEI and the addition of glucose enhance the O2 adsorption on the catalyst surface.

The PEI-GCN/Au composite demonstrates exceptional H2O2 production efficiency (270 μmol g-1 h-1) under visible light irradiation, using only glucose, H2O and O2 as reactants. As a result, both the biomimetic catalytic and photocatalytic reduction of O2 to H2O2 are enhanced, achieving a significant synergistic enhancement effect of 175%.

“This work establishes a paradigm of coupling biomimetic catalysis and photocatalysis for co-production of chemicals. It not only provides insights into the development of materials for efficient H2O2 production, but also introduces an innovative concept for integrating biocatalysis and photocatalysis,” said Prof. Luo Jianquan, the corresponding author of this study.

More information: Huiru Zhang et al, Biomimetic-photo-coupled catalysis for boosting H2O2 production, Chemical Engineering Journal (2024). DOI: 10.1016/j.cej.2024.149183

Provided by Chinese Academy of Sciences 

Team describes how to produce ‘green’ steel from toxic red mud

by Max Planck Society

Team describes how to produce 'green' steel from toxic red mud
Phase evolution of red mud with hydrogen plasma processing and mechanism of iron recovery. Credit: Nature (2024). DOI: 10.1038/s41586-023-06901-z

The production of aluminum generates around 180 million tons of toxic red mud every year. Scientists at the Max-Planck-Institut für Eisenforschung, a center for iron research, have now shown how green steel can be produced from aluminum production waste in a relatively simple way. In an electric arc furnace similar to those used in the steel industry for decades, they convert the iron oxide contained in the red mud into iron using hydrogen plasma.

With this process, almost 700 million tons of CO2-free steel could be produced from the 4 billion tons of red mud that have accumulated worldwide to date—which corresponds to a good third of annual steel production worldwide. As the Max Planck team shows, the process would also be economically viable.

According to forecasts, demand for steel and aluminum will increase by up to 60% by 2050. Yet the conventional production of these metals has a considerable impact on the environment. Eight percent of global CO2 emissions come from the steel industry, making it the sector with the highest greenhouse gas emissions. Meanwhile, aluminum industry produces around 180 million tons of red mud every year, which is highly alkaline and contains traces of heavy metals such as chromium.

In Australia, Brazil and China, among others, this waste is at best dried and disposed of in gigantic landfill sites, resulting in high processing costs. When it rains heavily, the red mud is often washed out of the landfill, and when it dries, the wind can blow it into the environment as dust.

In addition, the highly alkaline red mud corrodes the concrete walls of the landfills, resulting in red mud leaks that have already triggered environmental disasters on several occasions, for example in China in 2012 and in Hungary in 2010. In addition, large quantities of red mud are also simply disposed of in nature.

Potential to save 1.5 billion tons of CO2 in the steel industry

“Our process could simultaneously solve the waste problem of aluminum production and improve the steel industry’s carbon footprint,” says Matic Jovičevič-Klug, who played a key role in the work as a scientist at the Max-Planck-Institut für Eisenforschung. In a study published in the journal Nature, the team shows how red mud can be utilized as a raw material in the steel industry. This is because the waste from aluminum production consists of up to 60% iron oxide.

The Max Planck scientists melt the red mud in an electric arc furnace and simultaneously reduce the contained iron oxide to iron using a plasma that contains 10% hydrogen. The transformation, known in technical jargon as plasma reduction, takes just ten minutes, during which the liquid iron separates from the liquid oxides and can then be extracted easily. The iron is so pure that it can be processed directly into steel.

Green steel from toxic red mud
The generation, storage and hazards of red muds and solution with hydrogen plasma treatment. Credit: Nature (2024). DOI: 10.1038/s41586-023-06901-z

The remaining metal oxides are no longer corrosive and solidify on cooling to form a glass-like material that can be used as a filling material in the construction industry, for example. Other research groups have produced iron from red mud using a similar approach with coke, but this produces highly contaminated iron and large quantities of CO2. Using green hydrogen as a reducing agent avoids these greenhouse gas emissions.

“If green hydrogen would be used to produce iron from the 4 billion tons of red mud that have been generated in global aluminum production to date, the steel industry could save almost 1.5 billion tons of CO2,” says Isnaldi Souza Filho, Research Group Leader at the Max-Planck-Institut für Eisenforschung.

An economical process, including with green hydrogen and electricity

The heavy metals in the red mud can also be virtually neutralized using the process. “After reduction, we detected chromium in the iron,” says Jovičevič-Klug. “Other heavy and precious metals are also likely to go into the iron or into a separate area. That’s something we’ll investigate in further studies. Valuable metals could then be separated and reused.”

Additionally, heavy metals that remain in the metal oxides are firmly bound within them and can no longer be washed out with water, as can happen with red mud.

However, producing iron from red mud directly using hydrogen not only benefits the environment twice over; it pays off economically too, as the research team demonstrated in a cost analysis. With hydrogen and an electricity mix for the electric arc furnace from only partially renewable sources, the process is worthwhile, if the red mud contains 50% iron oxide or more.

If the costs for the disposal of the red mud are also considered, only 35% iron oxide is sufficient to make the process economical. With green hydrogen and electricity, at today’s costs—also taking into account the cost of landfilling the red mud—a proportion of 30 to 40% iron oxide is required for the resulting iron to be competitive on the market.

“These are conservative estimates because the costs for the disposal of the red mud are probably calculated rather low,” says Isnaldi Souza Filho. And there’s another advantage from a practical point of view: electric arc furnaces are widely used in the metal industry—including in aluminum smelters—as they are used to melt down scrap metal. In many cases, the industry would therefore need to invest only a little to become more sustainable.

“It was important for us to also consider economic aspects in our study,” says Dierk Raabe, Director at the Max-Planck-Institut für Eisenforschung. “Now it’s up to the industry to decide whether it will utilize the plasma reduction of red mud to iron.”

Strategies for enhancing the performance of nickel single-atom catalysts for the electroreduction of CO₂ to CO

by Ziyan Yang

Strategies for enhancing the performance of nickel single-atom catalysts for the electroreduction of CO2 to CO
Strategies to enhance the performance of nickel single-atom catalysts for the electroreduction of CO2 to CO. Credit: Yuhang Li, Chunzhong Li, East China University of Science and Technology, China

Electrocatalytic reduction of carbon dioxide (CO2) is considered as an effective strategy for mitigating the energy crisis and the greenhouse effect. Among the multiple reduction products, CO is regarded as having the highest market value as it is a crucial feedstock for Fischer-Tropsch process which can synthesize high-value long-chain hydrocarbons.

Since the carbon dioxide reduction reaction (CO2RR) has complex intermediates and multiple proton-coupled electron transfer processes, improving the reaction activity and products selectivity remain two great challenges.

Single-atom catalysts (SACs) have the advantages of high atom utilization, tunable coordination structure and excellent catalytic performance. In addition, due to the special electronic structure of nickel metal, it is more likely to lose electrons to form empty outermost d-orbitals and exhibit high activity and selectivity for CO2RR to generate CO.

A team of scientists have summarized the considerable progress of Ni SACs in recent years. Their work is published in Industrial Chemistry & Materials.

“Designing novel catalysts to improve the activity and selectivity of CO2RR is crucial for conquering the problem of energy crisis and environmental pollution,” said Yuhang Li, a Professor at East China University of Science and Technology, China,

“In this mini-review, we introduced three strategies used to improve the catalytic performance of Ni SACs, including different structures of supports, coordination structure regulation, and surface modification. In the end, we also summarized the existing challenges of Ni SACs and provided an outlook on future development in this field.”

SACs downsize the active sites to atomic scale and therefore get extraordinary electronic structure, powerful metal-support interactions, low-coordinated metal atoms, and maximum atom utilization at the same time. Hence, the application of SACs in CO2RR could effectively control the distribution of products and alleviate the cost of products separation.

“Some research based on crystal-field theory has indicated that the d-orbital electronic configurations of central metals are significant to the selectivity and activity of CO2RR,” Li said.

“In the case of nickel as the central metal atom, it is more likely to form the vacant outermost d-orbital to facilitate the electron transfer between the C atom of CO2 and the Ni atom. Therefore, the absorbed CO2 molecules can be efficiently activated. Ni SACs can also minimize the reaction potential of CO2-CO conversion, which is of great importance to enhance the selectivity towards CO.”

“Ni SACs have achieved continuous progress in recent years. From a microscopic point of view, the design strategies include choosing different substrates, regulating the coordination structure and modifying the catalyst surface. The electronic structure of the active center is the most crucial factor affecting catalytic performance,” Li said.

There is still tremendous potential for Ni SACs in future designs and applications. Precise modulation of the microstructure provides more active sites and therefore further enhances the performance of Ni SACs. Optimization of the electrolytic cells and development of more types of electrolytes can expand the range of Ni SACs applications and enable large-scale commercialization in the future.

In addition, researchers think that developing more in-situ techniques to gain deeper insights into the relationship between material structure and properties can provide valuable guidance for designing higher-value Ni SACs.

“In this mini-review, our main goal is to provide readers with the current research progress in Ni SACs in CO2RR and to show our insights into the design and application of single-atom catalysts,” Li said.

The research team includes Ziyan Yang, Rongzhen Chen, Ling Zhang, Yuhang Li, and Chunzhong Li from East China University of Science and Technology.

Solving an age-old mystery about crystal formation

by Laurie Fickman, University of Houston

Solving an age-old mystery about crystal formation
Peter Vekilov, University of Houston Frank Worley Professor of Chemical and Biomolecular Engineering, has published that incorporation of molecules into crystals occurs in two steps, divided by an intermediate state. Credit: University of Houston

A million years ago, the oldest known species to walk upright like a human, the Homo erectus, had a human-like fascination with crystals. Historians can even pin down the possible reasons—crystals didn’t look like anything around at the time—trees, valleys, mountains. Crystals were a material to ponder, a fascinating diversion for the mind.

To this day, the human preoccupation with the magic of crystals continues to fill the mind’s eye of scientists who have developed ways to use crystals for everything from malaria cures to solar cells and semiconductors, catalysts and optical elements. Over the years crystals have become crucial constituents of the technologies that enable modern civilization.

University of Houston researcher Peter Vekilov and Frank Worley Professor of Chemical and Biomolecular Engineering, have published in PNAS an answer to how crystals are formed and how molecules become a part of them.

“For decades crystal growth researchers have dreamt of elucidating the chemical reaction between incoming molecules and the unique sites on a crystal surface that accept them, the kinks,” said Vekilov. “The mechanism of that reaction, i.e., the characteristic time scale and length scale, possible intermediates and their stabilities, has remained elusive and subject to speculation for over 60 years.”

The main obstacle to deeper understanding has been the lack of data on how molecules join in, connected to the complicated process of moving from the solution to where they grow.

To unravel the chemical reaction between a molecule that dissolves in liquid (solute) and a kink, Vekilov mobilized two transformational strategies, one using full organic pairs and the second, using four solvents with distinct structures and functions. Working with the molecules, he combined state-of-the-art experimental techniques including time-resolved in situ atomic-force microscopy at near-molecular resolution, X-ray diffraction, absorption spectroscopy and scanning electron microcopy.

That’s when Vekilov made a revolutionary discovery: Incorporation into kinks may occur in two steps divided by an intermediate state and the stability of this middle state is key in how crystals grow. It basically decides how fast or slow the crystals form because it affects how easily things can join in during the process

Though the new discoveries don’t date back to Homo sapien times, they do solve a 40-year-old riddle for Vekilov.

“The notions of an intermediate state and its decisive role in crystal growth refute and replace the dominant idea in the field, brought up by A.A. Chernov, my Ph.D. advisor, that the activation barrier for growth is determined by the solute-solvent interactions in the solution bulk,” he said.

The new paradigm of two step incorporation, mediated by an intermediate state, could help in understanding how small parts in a liquid can influence the detailed shapes of crystals found in nature.

“Equally important, this paradigm will guide the search for solvents and additives that stabilize the intermediate state to slow down the growth of, for instance, undesired polymorphs,” Vekilov said.

Vekilov’s team includes Jeremy Palmer, Ernest J and Barbara M Henley Associate Professor of chemical and biomolecular engineering; former graduate students Rajshree Chakrabarti and Lakshmanji Verma; and Viktor G. Hadjiev, Texas Center for Superconductivity at UH.

More information: Rajshree Chakrabarti et al, The elementary reactions for incorporation into crystals, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2320201121

Provided by University of Houston 

Bifunctional electrocatalysts for efficient hydrogen production via overall hydrazine splitting

by Yongji Qin 

Bifunctional electrocatalysts for efficient hydrogen production via overall hydrazine splitting
Credit: Frontiers of Chemical Science and Engineering (2023). DOI: 10.1007/s11705-023-2373-1

Hydrogen is widely recognized as a promising clean energy source, primarily due to its high energy density and the absence of carbon emissions during its utilization. This characteristic makes hydrogen an ideal candidate for addressing the growing energy demand and mitigating the environmental impact associated with the excessive use of non-renewable fossil fuels over the past decades.

To harness renewable energy from sources like solar, wind, and tidal power, a compelling strategy involves the conversion of this volatile energy into hydrogen. This approach not only aids in meeting the energy demand gap but also contributes to the overall sustainability of human society.

Presently, overall water splitting (OWS) is considered a viable method for hydrogen production. OWS, powered by renewable energy, facilitates the generation of hydrogen through the hydrogen evolution reaction (HER) on the cathode.

However, the Faradic efficiency of hydrogen production is impeded by the anodic oxygen evolution reaction (OER), which is characterized by sluggish kinetics and high thermodynamic potential.

Consequently, there is a pressing need for the development of advanced electrocatalysts for OER or other oxidation reactions with swift kinetics and low thermodynamic potentials.

An alternative approach gaining traction is overall hydrazine splitting (OHzS) for hydrogen production, leveraging the anodic hydrazine oxidation reaction (HzOR). HzOR exhibits fewer electrons and faster kinetics compared to OER, making it a promising avenue. Nevertheless, a significant challenge remains in the synthesis of bifunctional electrocatalysts for both HER and HzOR with low overpotentials.

Recently, a research team in China introduced a novel solution in the form of a two-dimensional multifunctional layered double hydroxide derived from a metal-organic framework sheet precursor. This material is supported by nanoporous gold, providing high porosity. The study is published in the journal Frontiers of Chemical Science and Engineering.

Remarkably, this electrocatalyst demonstrates dual appealing activities for both HER and HzOR. In practical terms, the OHzS cell exhibits superior performance, requiring only a cell voltage of 0.984 V to deliver 10 mA∙cm-2, a notable improvement compared to the OWS system (1.849 V).

In addition, the electrolysis cell exhibits remarkable stability, operating continuously for more than 130 hours. This innovative approach not only enhances the efficiency of hydrogen production but also holds promise for a more sustainable and cleaner energy future.

Researchers develop cluster glass for fluorescence and nonlinear optical properties

by Liu Jia, Chinese Academy of Sciences

Researchers develop cluster glass for fluorescence and nonlinear optical properties
Graphical abstract. Credit: Angewandte Chemie International Edition (2024). DOI: 10.1002/anie.202400161

Glass can be synthesized through a novel “crystal-liquid-glass” phase transformation. Crystalline materials can be fine-tuned for desired properties such as improved mass transfer and optical properties through coordination chemistry and grid chemistry design principles.

However, how to induce the local structural disorder of crystalline materials to achieve glass transition remains a challenge because most of them undergo decomposition before melting.

In the metal-organic framework system, the exploration of glassy states is limited to a few model compounds such as ZIF-4, ZIF-62 and ZIF-8. There is a need to break the limitation of metals and ligands in the “crystal-liquid-glass” process and to develop the glass synthesis pathway of universal crystalline materials.

In a study published in Angewandte Chemie International Edition, a research group led by Prof. Zhang Jian and Prof. Fang Weihui from Fujian Institute of Research on the Structure of Matter of the Chinese Academy of Sciences reported the meltable aluminum molecular rings with fluorescence and nonlinear optical properties.

Inspired by the characteristics of deep eutectic solvent (DES) mixtures involving significant depressions in melting points compared to their neat constituent components, the researchers designed and synthesized the first examples of meltable aluminum oxo clusters via lattice doping with DESs at the molecular level.

This kind of molecular ring compound undergoes a crystal-liquid-glass process after heating. The abundant and strong hydrogen bonds between the aluminum molecular ring, DES components and the lattice solvent in the structure are considered to be the root cause of the lower melting point. This lattice doping bonding method provides a general preparation method for the development of cluster glass.

The researchers determined the composition changes of the compounds before and after melting and quenching by modern characterization methods and in situ temperature monitoring (TG-IR-MS). They tried to mix DES solvent with an empty Al8 ring by physical doping, and found no melting phenomenon in the mixture after heating, which proves the importance of doping the DES component in the lattice, that is, DES component forms a “supracluster” structure with aluminum molecular ring.

Owing to the plasticity of the cluster glass “soft material,” the researchers explored its machinability and optical properties. They prepared the bubble-free glass film by a simple “hot pressing” method under atmospheric pressure, and well maintained the luminescence and third-order nonlinear effect similar to that of the original crystal.

The forming of this cluster glass film does not require additional mixed media, which is different from the traditional substrate bonding method, revealing the advantages of cluster glass.

This study demonstrates the potential of aluminum-related glass prepared by the third most abundant metal in the Earth’s crust, for sustainable development. The strategy combining the aluminum molecular ring and ionic liquid component overcomes the limitation of metal and ligand type of crystal glass, and provides a better approach for the study of “crystal-liquid-glass.”

More information: San-Tai Wang et al, Meltable Aluminum Molecular Rings with Fluorescence and Nonlinear Optical Properties, Angewandte Chemie International Edition (2024). DOI: 10.1002/anie.202400161

Provided by Chinese Academy of Sciences 

Study reveals antiviral properties of solid wood surfaces

by University of Eastern Finland

Pioneering study reveals antiviral properties of solid wood surfaces
Graphical abstract. Credit: ACS Applied Materials & Interfaces (2024). DOI: 10.1021/acsami.4c02156

Researchers from the University of Eastern Finland (UEF) and the University of Jyväskylä (JYU) have collaborated to publish research on the antiviral capabilities of solid wood surfaces.

The study, led by the research groups of Varpu Marjomäki at JYU and Antti Haapala at UEF, investigated the antiviral potential of different wood species against enveloped coronaviruses and non-enveloped enteroviruses. The work has been published in ACS Applied Materials & Interfaces.

The COVID-19 pandemic and recurrent viral outbreaks have underscored the urgent need for innovative strategies to reduce virus transmission.

While wood has been a fundamental material in human environments for centuries, its antiviral properties have not been extensively explored—until now. This research is the first to systematically evaluate the inherent antiviral efficacy of the sawn wood material from various tree species, including both coniferous and deciduous trees, under different environmental conditions.

Key findings

  • Pine and Spruce: These coniferous species demonstrated excellent antiviral activity against enveloped coronaviruses, significantly reducing viral infectivity within just 10 to 15 minutes. However, their efficacy against non-enveloped enteroviruses was less pronounced.
  • Oak: This hardwood species was notably effective against non-enveloped enteroviruses, showcasing its potential for broader antiviral applications.
  • Chemical Composition: Analysis at UEF revealed that the antiviral properties are primarily governed by the chemical composition of the wood, including the presence of resin acids, terpenes, and phenolic compounds. These chemicals vary significantly between species and are influenced by environmental factors such as temperature and humidity.
  • Porosity and Absorption: While the porosity of wood and the absorption characteristics of viruses play a role, the study highlights that the chemical makeup of the wood is the key determinant in its antiviral functionality.

The research also found that thermal treatments and the addition of plastics to wood, such as in wood-plastic composites, can compromise the antiviral properties of the material. This insight opens new avenues for utilizing untreated or minimally processed wood surfaces in public health applications.

Future directions

The research teams from UEF and JYU will continue their investigation into the most effective antiviral components of wood and their mechanisms of action as part of the ongoing European Doctorate Program DESTINY. This future research aims to identify specific bioactive compounds that can be harnessed to develop sustainable and effective antiviral materials and coatings.

“This study marks a significant step forward in understanding how natural materials can be leveraged to enhance public health,” said Varpu Marjomäki, lead virologist at JYU.

“Our findings suggest that wood, a sustainable and widely available material, could play a crucial role in reducing viral transmission in various settings,” added Antti Haapala, lead material engineer at UEF.

“The synergistic roles between the different chemicals present are a continuing theme of investigation,” states Professor Haapala from Department of Chemistry.

A ‘liquid battery’ advance—strategies for electrocatalytic hydrogenation

by Stanford University

A 'liquid battery' advance
Credit: Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.4c02177

As California transitions rapidly to renewable fuels, it needs new technologies that can store power for the electric grid. Solar power drops at night and declines in winter. Wind power ebbs and flows. As a result, the state depends heavily on natural gas to smooth out highs and lows of renewable power.

“The electric grid uses energy at the same rate that you generate it, and if you’re not using it at that time, and you can’t store it, you must throw it away,” said Robert Waymouth, the Robert Eckles Swain Professor in Chemistry in the School of Humanities and Sciences.

Waymouth is leading a Stanford team to explore an emerging technology for renewable energy storage: liquid organic hydrogen carriers (LOHCs). Hydrogen is already used as fuel or a means for generating electricity, but containing and transporting it is tricky.

“We are developing a new strategy for selectively converting and long-term storing of electrical energy in liquid fuels,” said Waymouth, senior author of a study detailing this work in the Journal of the American Chemical Society. “We also discovered a novel, selective catalytic system for storing electrical energy in a liquid fuel without generating gaseous hydrogen.”

Liquid batteries

Batteries used to store electricity for the grid—plus smartphone and electric vehicle batteries—use lithium-ion technologies. Due to the scale of energy storage, researchers continue to search for systems that can supplement those technologies.

Among the candidates are LOHCs, which can store and release hydrogen using catalysts and elevated temperatures. Someday, LOHCs could widely function as “liquid batteries,” storing energy and efficiently returning it as usable fuel or electricity when needed.

The Waymouth team studies isopropanol and acetone as ingredients in hydrogen energy storage and release systems. Isopropanol—or rubbing alcohol—is a high-density liquid form of hydrogen that could be stored or transported through existing infrastructure until it’s time to use it as a fuel in a fuel cell or to release the hydrogen for use without emitting carbon dioxide.

Yet methods to produce isopropanol with electricity are inefficient. Two protons from water and two electrons can be converted into hydrogen gas, then a catalyst can produce isopropanol from this hydrogen.

“But you don’t want hydrogen gas in this process,” said Waymouth. “Its energy density per unit volume is low. We need a way to make isopropanol directly from protons and electrons without producing hydrogen gas.”

Daniel Marron, lead author of this study who recently completed his Stanford Ph.D. in chemistry, identified how to address this issue. He developed a catalyst system to combine two protons and two electrons with acetone to generate the LOHC isopropanol selectively, without generating hydrogen gas. He did this using iridium as the catalyst.

A key surprise was that cobaltocene was the magic additive. Cobaltocene, a chemical compound of cobalt, a non-precious metal, has long been used as a simple reducing agent and is relatively inexpensive. The researchers found that cobaltocene is unusually efficient when used as a co-catalyst in this reaction, directly delivering protons and electrons to the iridium catalyst rather than liberating hydrogen gas, as was previously expected.

A fundamental future

Cobalt is already a common material in batteries and in high demand, so the Stanford team is hoping their new understanding of cobaltocene’s properties could help scientists develop other catalysts for this process. For example, the researchers are exploring more abundant, non-precious earth metal catalysts, such as iron, to make future LOHC systems more affordable and scalable.

“This is basic fundamental science, but we think we have a new strategy for more selectively storing electrical energy in liquid fuels,” said Waymouth.

As this work evolves, the hope is that LOHC systems could improve energy storage for industry and energy sectors or for individual solar or wind farms.

And for all the complicated and challenging work behind the scenes, the process, as summarized by Waymouth, is actually quite elegant, “When you have excess energy, and there’s no demand for it on the grid, you store it as isopropanol. When you need the energy, you can return it as electricity.”

Additional Stanford co-authors are Conor Galvin, Ph.D. ’23, and Ph.D. student Julia Dressel. Waymouth is also a member of Stanford Bio-X and the Stanford Cancer Institute, a faculty fellow of Sarafan ChEM-H, and an affiliate of the Stanford Woods Institute for the Environment.

Team develops predictive tool for designing complex metal alloys that can withstand extreme environments

by Karyn Hede, Pacific Northwest National Laboratory

Metal alloys that can take the heat
Researchers have developed a tool to predict how new high-entropy alloys will behave under high-temperature oxidative environments. Development of new alloys is important for the aerospace and nuclear power industries. Credit: Nathan Johnson | Pacific Northwest National Laboratory

Cooks love stainless steel for its durability, rust resistance and even cooking when heated. But few know the secret that makes stainless steel so popular. It’s the metal chromium in stainless steel, which reacts with oxygen in the air to form a stable and protective thin coating for protecting the steel underneath.

These days, scientists and engineers are working to design alloys that can resist extreme environments for applications such as nuclear fusion reactors, hypersonic flights and high-temperature jet engines. For such extreme applications, scientists are experimenting with complex combinations of many metals mixed in equal proportions in what are called multi-principal element alloys or medium- to high-entropy alloys. These alloys aim to achieve design goals such as strength, toughness, resistance to corrosion and so on.

Specifically, researchers seek alloys resistant to corrosion that can happen when metals react with oxygen in the atmosphere, a process called oxidation. These alloys are typically tested in a “cook-and-look” procedure where alloy materials are exposed to high-temperature oxidation environments to see how they respond.

But now, a multidisciplinary research team led by scientists at the Department of Energy’s Pacific Northwest National Laboratory and North Carolina State University combined atomic-scale experiments with theory to create a tool to predict how such high-entropy alloys will behave under high-temperature oxidative environments. The research, published in the journal Nature Communications, offers a road map toward rapid design and testing cycles for oxidation-resistant complex metal alloys.

“We are working toward developing an atomic-scale model for material degradation of these complex alloys, which then can be applied to design next-generation alloys with superior resistance to extreme environments for a wide variety of applications such as the aerospace and nuclear power industries,” said Arun Devaraj, co-principal investigator of the study and a PNNL materials scientist specializing in understanding metal degradation in extreme environments.

“The goal here is to find ways to rapidly identify medium- to high-entropy alloys with the desired properties and oxidation resistance for your chosen application.”

Metal alloys that can take the heat
Materials scientist Arun Devaraj works at an atom probe tomography instrument at Pacific Northwest National Laboratory. This precision instrument can show the placement of atoms in tiny samples of materials, such as metal alloys. Credit: Andrea Starr | Pacific Northwest National Laboratory

A complex alloy recipe

For their recent experiments, the research team studied the degradation of a high-entropy alloy with equal amounts of the metals cobalt, chromium, iron, nickel and manganese (CoCrFeNiMn, also called the Cantor alloy). The research team examined oxide formed on the Cantor alloy using a variety of advanced atomic-scale methods to understand how each element arranges itself in the alloy and the oxide.

They discovered that chromium and manganese tend to migrate quickly toward the surface and form stable chromium and manganese oxides. Subsequently, iron and cobalt diffuse through these oxides to form additional layers.

By adding a small amount of aluminum, they discovered that aluminum oxide can act as a barrier for other elements migrating to form the oxide, thereby reducing the overall oxidation of the aluminum-containing Cantor alloy and increasing its resistance to degradation at high temperatures.

“This work sheds light on the mechanisms of oxidation in complex alloys at the atomic scale,” said Bharat Gwalani, co-corresponding author of the study. Gwalani began the study while a scientist at PNNL and continued the research in his current role as an assistant professor of materials science and engineering at North Carolina State University. He added, “by understanding the fundamental mechanisms involved, this work gives us a deeper understanding of oxidation across all complex alloys.”

Metal alloys that can take the heat
Microscopic samples of complex metal alloy are placed on a sampling vessel to enter the atom probe tomography instrument. Credit: Andrea Starr | Pacific Northwest National Laboratory

Predictive models

“Right now there are no universally applicable governing models to extrapolate how a given complex, multi-principal element alloy will oxidize and degrade over time in a high-temperature oxidation environment,” said Devaraj. “This is a substantial step in that direction.”

The team’s careful analysis revealed some universal rules that can predict how the oxidation process will proceed in these complex alloys. Computational colleagues from NCSU developed a model called the Preferential Interactivity Parameter for early prediction of oxidation behavior in complex metal alloys.

Ultimately, the research team expects to expand this research to develop complex alloys with exceptional high-temperature properties, and to do so very quickly by rapid sampling and analysis. The ultimate goal is to choose a combination of elements that favor the formation of an adherent oxide, said Devaraj. “You know oxide formation will happen, but you want to have a very stable oxide that will be protective, that would not change over time, and would withstand extreme heat inside a rocket engine or nuclear reactors.”

A next step will be to introduce automated experimentation and integrate additive manufacturing methods, along with advanced artificial intelligence, to rapidly evaluate promising new alloys. That project is now getting underway at PNNL as a part of the Adaptive Tunability for Synthesis and Control via the Autonomous Learning on Edge (AT SCALE) Initiative.

“That kind of discovery loop for materials discovery will be very relevant for further expanding our knowledge of these novel alloys,” said Devaraj, who also has a joint faculty appointment at the Colorado School of Mines.

In addition to Gwalani and Devaraj, PNNL scientists Sten Lambeets, Matthew Olszta, Anil Krishna Battu and Thevuthasan Suntharampillai contributed; as well as Martin Thuo, Aram Amassian, Andrew Martin, Aniruddha Malakar, and Boyu Guo of NCSU; Elizabeth Kautz, an assistant professor of nuclear engineering at North Carolina State, who also has a joint appointment with PNNL; Feipeng Yang and Jinghua Guo of Lawrence Berkeley National Laboratory; and Ruipeng Li of Brookhaven National Laboratory.

To investigate the arrangement of atoms within the samples, the research team used in situ atom probe tomography at PNNL. These results were correlated with electron microscopy and synchrotron-based grazing incidence wide-angle X-ray scattering at the National Synchrotron Light Source II, BNL, and X-ray absorption measurements conducted at the Advanced Light Source, LBNL.