There is an old saying in the biorefining industry that "You can make anything from lignin, except money." This bio-based compound is abundant and full of potential, but commercializing it remains a challenge.This may soon no longer be the case with an innovative approach by chemists from Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences and their colleagues to harness lignin condensation — often considered a nuisance — for efficient utilization of lignocellulose. This opens up a holistic pathway for maximizing the potential of wood biomass and advancing towards a more sustainable future.Their results are published in Nature on May 29th.Lignin is a complex polymer in lignocellulose — a structural component found in the cell walls of plants and a potential organic feedstock for production of biofuel and bio-based material. However, when chemically treated, lignin tends to form new C–C bonds, a process known as condensation, which makes its structure complex and less reactive. This hampers further processing and consequently limits the effective utilization of lignocellulose for production of green chemicals and materials.Various efforts have been made to sidestep this detrimental condensation. Researchers at DICP, however, went against the grain and found a way to use lignin condensation to their advantage."Rather than suppressing the undesired reaction, our aim was to leverage lignin's proclivity toward condensation by restructuring the condensation reaction pathway through explicit arylation with lignin-derived phenols," said WANG Feng, a professor at DICP and the corresponding author of this study.Arylation is a chemical process in which an aryl group, a type of aromatic compound, is introduced into a molecule via Friedel-Crafts Alkylation. By directing specific bond formations through this process, the researchers were able to obtain a high yield of condensed lignin, which was further processed to produce benign bisphenols — versatile compounds with applications ranging from plastics to adhesives that could serve as potential replacements for fossil-based counterparts."Historically, lignin has been viewed as waste or a hindrance in biorefinery processes," WANG said. "However, through our studies, we have come to recognize that lignin is, rather than a waste product, an invaluable and indispensable natural resource for fostering sustainability. Our slogan therefore is 'Lignin Matters' and we advocate for the development of strategies aimed at efficiently converting lignin into valuable chemicals and materials."By maximizing lignocellulose's value, the researchers' approach contributes to a more holistic approach to biomass utilization, aligning with the goals of green biorefineries."Our ultimate goal is to establish an industrially competitive biorefinery, revolutionizing the production of renewable chemicals and biomaterials," WANG said. "I hope in the future T-shirts and plastic commodities can be directly manufactured from wood or grasses."

Transition metal telluride nanosheets have shown enormous promise for fundamental research and other applications across a rainbow of different fields, but until now, mass fabrication has been impossible, leaving the material as something of a laboratory curiosity rather than an industrial reality. But a team of researchers has recently developed a novel exfoliation process—the use of chemical solutions to peel off thin layers from their parent compounds, creating atomically thin sheets—that looks set to finally deliver on the ultra-thin substance's promise.The researchers describe their fabrication process in a study published in Nature on April 3.In the world of ultra-thin or 'two-dimensional' materials—those containing just a single layer of atoms—transition metal telluride (TMT) nanosheets have in recent years caused great excitement amongst chemists and materials scientists for their particularly unusual properties. These compounds, made of tellurium and any of the elements in the 'middle' of the periodic table (groups 3-12), enjoy a range of states from semi metallic to semiconducting, insulating and superconducting, and even more exotic states, as well as magnetic and unique catalytic activity.These properties offer a range of potential applications across electronics, energy storage, catalysis, and sensing. In particular, TMT nanosheets are being explored as novel electrode materials in batteries and supercapacitors—essential for the clean transition—due to their high conductivity and large surface area.TMT nanosheets can also be used as electrocatalysts for lithium-oxygen batteries, improving their efficiency and performance. Other potential applications in emerging technologies include photovoltaics and thermoelectrics, hydrogen production, and filtration and separation. They have even been found to display interesting quantum phenomena, such as quantum oscillations and giant magnetoresistance."The list of industries that would enjoy significant efficiency improvements from the mass production of TMT nanosheets is extremely long," said team leader WU Zhong-Shuai, a chemist with the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences. "This is why this 2D material is potentially so exciting."Unfortunately, despite various attempts at exfoliation of high-quality TMT nanosheets, preserving high crystallinity while achieving large nanosheet size and ultrathin feature continues to be a significant challenge. The methods devised so far are not scalable due to long processing times. They also often require toxic chemicals. Thus, the properties of TMT nanosheets have remained an interesting laboratory phenomenon that cannot quite make the leap to mass production and industrial application.The team finally cracked this problem via a simplified process of lithiation, hydrolysis and finally the nanosheet exfoliation.First, a bulk quantity of metal telluride crystals was prepared using chemical vapor transport—a method commonly used in chemistry to transport solid compounds from one location to another using a carrier gas. When the reaction vessel is heated, the transporting agent vaporizes and carries the solid compound with it as a vapor. The vapor travels through the reaction vessel and may encounter a cooler surface, where the compound can deposit and form crystals. This allows for the controlled growth of crystals or very thin films of the desired compound. In this case, the prepared telluride crystals are then mixed with lithium borohydride. This process involves the placing of lithium ions in between the layers of the metal telluride crystals, leading to the formation of an intermediate, 'lithiated' compound.The lithiated intermediate compound is then rapidly drenched with water, which results in "exfoliation," or stripping of the lithiated metal telluride crystals into nanosheets in seconds.Finally, the exfoliated metal telluride nanosheets are collected and characterized based on their shape and size, allowing them to be further processed into different forms such as films, inks and composites, depending on the desired application.The whole process takes just ten minutes for the lithiation and seconds for the hydrolysis. The method is capable of producing high-quality TMT nanosheets of varying desired thicknesses with very high yields.When testing the nanosheets, the researchers found that their charge storage, high-rate capacity, and stability made them promise for applications in lithium batteries and micro-supercapacitors.They believe that their method is essentially ready for commercialization, but they also want to conduct further studies to characterize the properties and behavior of their nanosheets, as well as further refine and optimize the lithiation and exfoliation stages.

Scientists have observed so-called 'roaming' chemical reactions, those that at certain points move away from the lowest minimum energy 'path of least resistance', in highly excited energy states for the first timeChemical reactions are supposed to occur along their minimum energy paths. In recent years, so-called roaming reactions that stray far from this path have begun to be observed, but only for chemical species in their ground state or, at most, their first excited state. However, researchers have now observed a roaming reaction even in highly excited energy states.The researchers from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) described their findings in a paper appearing in Science on Feb. 16.Until recently, chemists had assumed that chemical reactions occur along what they call minimum energy paths—the reaction pathway that uses the lowest amount of energy between the starting stable configuration of a molecule and its final stable state. At a certain point in any chemical reaction, there lies a “transition state", at which the potential energy has a maximum value. This can be thought of as akin to a ball rolling up a hill and down again. But that transition state at the "top of the hill" still lies along the minimum energy path. Reactions aren't supposed to stray away from this path of least resistance.But in 2004, researchers exploring the breakdown of formaldehyde when being bombarded by photons (a chemical reaction called "photodissociation") were shocked to discover that there are chemical reactions that can, in fact, stray well away from the minimum energy path.This straying, or more properly "roaming," happens when the expected cleavage of a chemical bond instead becomes "frustrated": a component of a molecule begins to escape its parent molecule, but finds it does not have sufficient energy to do so. So instead, the component just orbits the remaining molecular fragment in a non-minimum-energy state. It continues this orbit until it bumps into a reactive site (the physical location on a molecule where the reaction takes place and a new chemical bond is formed) of another molecule, returning to the minimum energy path.Since then, these "roaming reactions" have been found to not just be occasional occurrences, but common ones."It turned out that roaming is a general aspect of chemical reactivity that had never been noticed before," said FU Bina, one of the corresponding authors of the paper from DICP.Further investigations have observed roaming reactions in both ground states—a molecule's lowest possible energy, and in their first excited states. When absorbing energy, an electron in a molecule jumps up to higher energy levels, called excited states. But roaming had only been observed in the first such excited states, not in any subsequent, higher excited states. Nor has roaming been observed to lead to the generation of electronically excited products of the chemical reaction.The authors of the paper however reported they had observed roaming in a highly excited state for the first time, in this case during the photodissociation of sulfur dioxide (SO2) molecules into sulfur and oxygen (a molecule of SO2 breaks down into an atom of sulfur, S, and one molecule of oxygen, O2, when bombarded by light).Their results revealed two different possible pathways for dissociation. One proceeds along the expected minimum energy path to produce a "vibrationally colder" O2 molecule, and the other yields a "vibrationally hotter" O2 molecule in its electronically excited state."The latter reaction does this via a roaming pathway involving a sort of 'blob' of a single oxygen atom, what we call an 'intramolecular O- abstraction', during a motion in which the molecule reorients itself," said YUAN Kaijun, another corresponding author of the paper from DICP.Any time there is an increased probability of encountering "frustrated bond cleavage," there is an increased likelihood of roaming reactions in highly excited states and production of electronically excited products. Such roaming dynamics may turn out to be the rule, the researchers believe, rather than the exception for molecular photodissociation through highly excited states.The researchers were interested in SO2 in particular, given its importance in the Earth's atmosphere. Changes in the abundance of SO2 impact the radiation balance of the planet and thus the climate, and SO2 from volcanic eruptions is one of the two most important sources of aerosols in the stratosphere, and electronically excited products themselves react very differently in the atmosphere, in space, and in combustion. Finally, photodissociation of SO2 could be of great importance for understanding the sources of molecular oxygen (O2) in the Earth's primitive atmosphere prior to the emergence of life.As a result of their findings, the researchers argue that the roaming mechanism of molecular oxygen production should now be incorporated into photochemical modelling of the atmospheres of planets with rich volcanic outgassing of SO2.

The world's largest ethanol production equipment, with an annual output of 600,000 tonnes, went into trial on Thursday in Huaibei City, east China's Anhui Province.The equipment can convert coke oven gas into ethanol, which will massively increase the added value of coal and provide a feasible way for the low-carbon development of steel and petrochemical industries.Adopting the advanced technology jointly developed by the Dalian Institute of Chemical Physics (DICP) under the Chinese Academy of Sciences and Shaanxi Yanchang Petroleum (Group) Co., Ltd., the equipment was constructed by Tanxin Technology Co., LTD. under the Huaibei Mining Group.Ethanol is an excellent gasoline additive and a vital basic chemical. It is produced mainly by the United States, Brazil, and other countries, with crops such as grain and sugarcane as raw materials, and is used as fuel ethanol.China's ethanol market is in great demand, said the research team leader Liu Zhongmin, director of the DICP and an academician of the Chinese Academy of Engineering. He added the gap in fuel ethanol in China was about 10 million tonnes in 2022.The research team developed an advanced technology, DMTE, using syngas as raw material to produce absolute ethanol by carbonylation of dimethyl ether followed by hydrogenation of methyl acetate.The team has continuously upgraded the technology and the catalyst and optimized the reaction process, laying a solid foundation for large-scale industrialization.The trial operation of the equipment at Tanxin Technology Co., LTD. has verified the advanced nature and reliability of DMTE, said the general manager of Tanxin Technology Co., LTD. Li Wei.Until now, the team has signed 13 sets of DMTE technology implementation license contracts, including two sets exported, Liu said.The large-scale production of non-grain ethanol is pivotal in ensuring China's food security, energy security, chemical industry chain, and supply chain security, Liu said. (by Xinhua)This aerial photo taken on Dec. 28, 2023 shows the ethanol production equipment with an annual output of 600,000 tonnes at Tanxin Technology Co., LTD. under the Huaibei Mining Group in Huaibei, east China's Anhui Province. The world's largest ethanol production equipment, with an annual output of 600,000 tonnes, went into trial on Thursday in Huaibei City, east China's Anhui Province (Photo by JIN Liwang)

Researchers have reported a strategy to disentangle the activity-selectivity tradeoff for direct conversion of syngas, a mixture of carbon monoxide and hydrogen, into desirable ethylene, propylene, and butylene. These hydrocarbons are known as light olefins and are the most-used building blocks for plastics."Activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. A higher activity means higher efficiency in converting feedstock to products, thereby reducing energy consumption," said JIAO Feng, an associate professor at the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences in Dalian, China. "Selectivity reflects the percentage of the desired products, for example ethylene, propylene and butylene in this case, which determines the economy of the technology."For almost a century, a process called the Fischer-Tropsch synthesis (FTS) was used for direct syngas conversion with iron or cobalt-based catalysts for synthesis of chemicals. However, selectivity for light olefins remained a challenge. An alternative process, named OXZEO, developed 6 years ago by the same research team using metal oxide-zeolite catalyst improved light-olefin selectivity far beyond the theoretical limit of FTS. Despite the significant progress over the years, the activity is still limited by the activity-selectivity tradeoff.For example, when FTS is used to convert syngas to light olefins, the yield amounts to around 26%. Using traditional silicon containing zeotypes within the OXZEO catalyst concept, the light-olefins yield has so far maxed out at 27%. These limits originate from activity-selectivity tradeoff, a long-standing challenge in catalysis. This can be traced to the catalytic sites for both the target and side reactions, which are usually entangled on technical catalysts.Now, in a paper published in the journal Science on May, 19, a team led by Dr. JIAO, Prof. PAN and Prof. BAO has shown that incorporating germanium-substituted aluminophosphates within the OXZEO catalyst concept can disentangle the desired target reaction from the undesired secondary reactions. It enhances the conversion of the intermediates to produce olefins by creating more active sites and in turn generation of intermediates but without degrading the selectivity of light olefins. With this new strategy, researchers simultaneously achieved high CO conversion and light-olefins selectivity and the yield reached an unprecedented 48% under optimized conditions.To validate the mechanism, researchers also studied silicon-substitute and magnesium-substitute aluminophosphates and tested them in similar scenarios. The active sites of these two zeotypes cannot efficiently shield the side reaction of hydrogenation and oligomerization, thereby the activity-selectivity tradeoff cannot be overcome, despite optimizing the acid site density or reaction conditions."Separating the active sites of the two key steps of syngas conversion via OXZEO catalysts, and increasing the active site density and modulating its properties for kinetics of intermediate transport and reactions within the zeotype confined pores provides one effective solution for syngas conversion to light olefins," said PAN, professor at DICP. "We expect that this can be applicable to analogous bifunctional catalysis in other reactions and will be of interest for further development of zeolite catalysis.""If it can be incorporated with green hydrogen energy technology in the future, it will make significant contribution to the goal of carbon neutrality." said Xinhe Bao, professor at DICP and the president of the University of Science and Technology of China.

Materials that can conduct negatively charged hydrogen atoms in ambient conditions would pave the way for advanced clean energy storage and electrochemical conversion technologies. A research team from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) demonstrated a technique that enables a room-temperature all-solid-state hydride cell by introducing and exploiting defects in the lattice structure of rare earth hydrides.Their study was published in Nature on April 5.Solid materials that conduct lithium, sodium and hydrogen cations have been used in batteries and fuel cells. Under certain conditions, some of the materials transition to superionic states where ions move as fast as they do in liquids by skipping through the rigid crystal structure. This phenomenon is advantageous for chemical and energy conversions as it allows ions to move without a liquid or soft membrane to separate the electrodes. However, few solid-state materials can reach this state under ambient conditions."Materials that exhibit superionic conduction at ambient conditions would provide huge opportunities for constructing brand new all-solid-state hydride batteries, fuel cells and electrochemical cells for the storage and conversion of clean energy," said Prof. CHEN Ping, study author from DICP.With strong reducibility and high redox potential, hydride ion (H-) conductors have emerged as promising candidates for this technology. Several H- conductors have already been developed in recent years, including alkaline earth metal hydrides and oxyhydrides of alkaline earth and rare earth metals, which are known for fast hydrogen migration. But none of the materials developed could achieve superionic conduction at ambient conditions —until the DICP team took a new approach.The DICP research team targeted the structure and morphology of trihydrides — hyrdrides containing three atoms of hydrogen per molecule — of certain rare earth elements (REHx), including Lanthanum (La).Strategies to enhance electronic conductivities typically seek to diminish crystallographic imperfections for applications like metallic nanowire interconnects and nanostructured photovoltaic semiconductors. In this study, however, the research team purposely created abundant discrete nanosized grains and lattice defects to disturb the path of electron transport in REHx and suppress the electronic conductivity. This is different from engineering conventional materials for ion conduction, which relies upon the consistent structure of high crystallinity.The research team observed how H- ions diffused easily in REHx lattices by hopping between octahedral and tetrahedral sites in the crystal and across interfaces or grain boundaries. Electrons, on the other hand, encountered substantial scattering at grain boundaries, particle surfaces and other traps, which brought down the electronic conductivities by three to five orders of magnitude from those of their well-crystallized counterparts."By creating nano-sized grains, defects and other crystalline mismatched zones in a known ionic-electronic mixed conductor, we demonstrated that the electronic conductivity of LaHx (x ≈ 2.94) can be largely suppressed by five orders of magnitude," said CHEN. "Engineering such a material could transform LaHx into a pure hydride ion conductor with record high conductivities in the temperature range of -40 to 80 ℃."The researchers effectively suppressed electron conduction of LaHx by decreasing the particle size and distorting the lattice via high-energy ball milling, which involves subjecting the material to high-energy collisions. With fast H- conduction and a high ion transfer number, the deformed LaHx material would enable a hydride ion battery to operate at room temperature or lower."This work demonstrates the effectiveness of lattice deformation in suppressing electron conduction in REHx," said CHEN.The researchers plan to explore the physics underneath the phenomenon and extend the method developed in this study to other hydride materials to broaden the material scope for pure H- conductors."Our near-term goal is to demonstrate a brand new all-solid-state hydride ion battery that is of practical potential," said CHEN.This work was jointly supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, Youth Innovation PromotionAssociation CAS and the Liaoning Revitalization Talents Program.Other contributors include ZHANG Weijin, CUI Jirong, WANG Shangshang, CAO Hujun, JIANG Qike, GUO Jianping and HE Teng from DICP; WU Anan from Xiamen University and XIA Yuanhua from the China Academy of Engineering Physics.Main authors of the study (Image by LIANG Xiao)