Sugar is a common dietary component, yet excessive intake has well-documented negative health impacts. Steviol glycosides, natural sweeteners extracted from Stevia rebaudiana, are widely used as sucrose substitutes due to their high sweetness and low caloric value. Among them, Rebaudioside M (Reb M) is regarded as a next-generation, high-value steviol glycoside product because of its intense sweetness and superior taste profile. However, the natural abundance of Reb M in stevia is extremely low, creating the need for efficient biosynthetic methods to meet market demand.Until now, the key enzyme catalyzing the conversion of Rebaudioside D (Reb D) to Reb M in the biosynthetic pathway had not been clearly identified and was generally assumed to be UGT76G1. However, UGT76G1 exhibits strict regioselectivity for the C13 position of steviol glycosides, while its catalytic activity at the C19 position is very weak.In a recent study published in Proceedings of the National Academy of Sciences, a team led by Prof. YIN Heng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) identified the key glycosyltransferase that catalyzes the conversion of Reb D to Reb M and revealed the molecular mechanism underlying its substrate regioselectivity. By applying semi-rational design, the team further engineered several tool enzymes with enhanced performance, enabling the efficient synthesis of Reb M.Key role of UGT76G4 in Rebaudioside M synthesis and the structural basis of its substrate regioselectivity. (Image by WANG Yu and LI Tang)Researchers identified and characterized UGT76G4—a natural variant of UGT76G1—from a high-Reb M producing Stevia cultivar. They discovered that UGT76G4 exhibited regioselectivity toward the C19 position of steviol glycosides in both in vivo and in vitro assays, thereby confirming it as the key enzyme catalyzing the conversion of Reb D to Reb M.Furthermore, researchers systematically elucidated the molecular basis of UGT76G4 regioselectivity, identifying residue G200 as critical for its C19 catalytic activity. Based on this mechanistic insight, they engineered UGT76G4 variants capable of efficiently synthesizing Reb M using Rebaudioside E (Reb E) and Reb D as substrates."This work not only clarifies the long standing question of which enzyme is responsible for Reb M biosynthesis, but also provides engineered biocatalysts to enable the efficient production of this next generation natural sweetener," said Prof. YIN.

Anion exchange membrane (AEM) water electrolysis is widely recognized as a key technology for next-generation green hydrogen production. Currently, most AEM systems rely on alkaline supporting electrolytes, such as potassium hydroxide, which can cause issues including bipolar plate corrosion, shunt current, and accelerated membrane degradation.Achieving stable operation with pure water feed is the goal for AEM water electrolysis. However, this has been hindered by bottlenecks, including instability of the membrane-electrode three-phase interface, limited current density, and poor durability. These issues have constrained progress toward industrialization.In a recent study published in Advanced Energy Materials, a team led by Prof. SHAO Zhigang and Prof. ZHAO Yun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) enhanced the durability of pure water-fed AEM electrolysis, achieving over 2,400 hours of stable operation through membrane-electrode interface engineering.Conventional AEM (Tg > 200°C) in MEA with KOH supporting electrolyte (left); QPS-x%-R-PEEK (Tg < 100°C) in MEA for pure water-fed AEM water electrolysis (right) (Image by HUANG Riyang and ZHAO Yun)Researchers used poly(ether-ether-ketone) (PEEK), known for its strong mechanical properties, as the base membrane, and introduced quaternized polystyrene (QPS) with a low glass transition temperature as the resin to develop a new type of AEM composite membrane.During the hot-pressing process and cell operation, the QPS material transitions from a glassy state to a highly elastic state, acting like a "glue". This not only reinforces the bonding strength of the membrane-electrode interface but also facilitates efficient hydroxide ion (OH-) transport.Experimental results showed that the interfacial bonding strength between the composite membrane and the electrode reached 23.5 N mm-1 - two orders of magnitude higher than that of the traditional poly(aryl piperidine) membrane with a high glass transition temperature above 200℃. The optimized membrane-electrode structure enhanced OH- transport, enabling the pure water electrolysis system to reach a current density of 1,200 mA cm-2 at 80℃ and 1.8 V.Moreover, the system achieved continuous operation for 2,464 hours at 500 mA cm-2. To further validate scalability, researchers tested a large-area 160 cm2 cell, which ran continuously for 160 hours at 200 mA cm-2, demonstrating strong potential for industrial application."Our work represents an important step toward scalable, industrially relevant green hydrogen production using AEM technology," said Prof. SHAO.

Ethylene, a key feedstock for producing a wide range of commodity chemicals, is traditionally obtained through steam cracking of petroleum-derived hydrocarbons. Recently, the semi-hydrogenation of coal-derived acetylene to produce ethylene has emerged as a promising non-petroleum-based alternative. In particular, electrocatalytic acetylene semi-hydrogenation (EASH), driven by renewable energy, offers several advantages, such as using of water as a hydrogen source, operating under ambient reaction conditions, and producing low carbon emissions.However, the practical application of ethylene electrosynthesis via EASH has been hindered by slow reaction rate, limited ethylene selectivity, and low energy efficiency. While previous studies have primarily focused on tuning catalytic active sites at the nanoscale and atomic scale, the critical role of mesoscopic mass transport within electrodes has often been overlooked.In a study published in Angewandte Chemie International Edition, a research team led by Profs. BAO Xinhe and GAO Dunfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) achieved ethylene electrosynthesis from acetylene at ampere-level current density by promoting interparticle mass transport.Ethylene electrosynthesis from acetylene at ampere-level current density via promoting interparticle mass transport (Image by YAN Chuanchuan)Researchers quantitatively demonstrated the crucial role of interparticle mass transport on EASH performance. By increasing the average interparticle distance of Cu cubes, they improved acetylene adsorption and ethylene desorption, leading to enhanced EASH performance. The Cu cube electrode with a large average interparticle distance of 265 nm exhibits an ethylene Faradaic efficiency of 97.4% at a current density of 1.0 A cm−2 and a maximum ethylene partial current density of 1.5 A cm−2 in an alkaline membrane electrode assembly electrolyzer.Moreover, researchers revealed that increasing the interparticle distance of Cu cubes effectively promotes mass transport, enabling efficient ethylene electrosynthesis under industrially relevant conditions."Our study demonstrates the key role of mesoscopic mass transport in electrocatalysis," said Prof. GAO. "This factor should be considered in designing high-performance electrocatalytic systems."

Photoinduced electron/energy transfer reversible addition - fragmentation chain-transfer (PET-RAFT) polymerization enables precise light-controlled polymer growth. While conventional near-infrared strategies often rely on nonlinear optical processes such as two-photon absorption or photon upconversion, which typically require high-intensity laser excitation. In contrast, direct shortwave infrared (SWIR) light-driven PET-RAFT offers distinct advantages, including higher selectivity, deeper tissue penetration, and potential applications in 3D printing and transdermal polymerization. However, efficient photocatalysts that can directly utilize SWIR photons remain rareCuInSe2/CuInS2 quantum dots for SWIR-driven PET-RAFT polymerization (Image by DU Jun)In a study published in Journal of the American Chemical Society, a research team led by Prof. WU Kaifeng and Prof. DU Jun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Cyrille Boyer at the University of New South Wales, achieved living radical polymerization using low-toxicity copper indium selenide (CuInSe2) quantum dots (QDs), extending PET-RAFT excitation into the SWIR region at 1,050 nm.Researchers synthesized highly luminescent CuInSe2/CuInS2 QDs with an absorption onset extended to 1,100 nm and hybridized them with 4-Cyano-4-(dodecylsulfanylthiocarbonyl)sulfanylpentanoic acid as a photocatalyst. Under 1,050 nm excitation, this hybrid system effectively triggered PET-RAFT polymerization, achieving efficient polymerization through 3 mm of biological tissue.Furthermore, researchers revealed that long-lived shallow defect-state electrons in CuInSe2 QDs play a key role during organic photochemical reactions, providing theoretical guidance for the development of high-performance SWIR photocatalysts."With further optimization of QDs, this strategy could enable efficient polymerization at even longer wavelengths, paving the way for SWIR-driven synthesis of advanced functional polymer materials," said Prof. DU.

Efficient energy conversion and storage technologies are critical for achieving China's carbon peak and carbon neutrality goals. Solid oxide electrolysis cells (SOECs) offer a promising route by converting renewable electricity into storable chemical fuels through high-temperature carbon dioxide electrolysis. However, sluggish oxygen evolution reaction (OER) at the anode poses a major challenge due to its complex four-electron transfer process.Perovskite oxides are regarded as promising candidates for SOEC anodes due to their high mixed ionic–electronic conductivity and tunable electronic structures. Previous studies have revealed a volcano-shaped correlation between the occupancy of the 3d electron with eg symmetry in perovskite oxide and intrinsic OER activity in alkaline solution, with peak activity occurring at a near-unity eg occupancy. However, the intrinsic connection between eg occupancy and high-temperature OER activity has remained unclear.Spin-state tuning in PrFeO3-δ perovskite for high-temperature oxygen evolution reaction (Image by YU Jingcheng)In a study published in Journal of the American Chemical Society, Assoc. Prof. SONG Yuefeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), along with Prof. WANG Guoxiong from Fudan University, developed a series of alkaline-earth-metal-doped perovskites, Pr0.5Ae0.5FeO3−δ (Ae = Ca, Sr, Ba, labeled as PCF, PSF, PBF), to investigate the impact of electronic structure tuning on high-temperature OER performance.Researchers found that OER activity increases with larger dopant ionic radius. They showed that the PBF achieves a current density of 3.33 A cm−2 at 2.0 V and 800 °C.Detailed analyses revealed that alkaline earth metal doping enhances Fe 3d-O 2p hybridization, lowers charge-transfer energy, and promotes oxygen ions migration and surface spillover, thereby accelerating the OER process. Moreover, magnetic measurements showed that Ba doping induces a spin-state transition from high-spin Fe3+ (t2g3eg2) to low-spin Fe4+ (t2g4eg0), resulting in reduced eg occupancy and accelerated oxygen kinetics."Our study establishes spin-state tuning as a key strategy to boost high-temperature OER activity, and provides fundamental guidance for electronic structure engineering in the design of advanced SOEC anode materials," said Dr. SONG.

Contemporary industrial nitrogen fixation largely relies on the energy-intensive Haber-Bosch process, which operates under extremely high temperatures and pressures. Metal carbides, as a promising class of catalytic materials, have recently attracted attention in heterogeneous catalysis research. Understanding their nitrogen activation mechanisms at the molecular and electronic levels is crucial for developing next-generation catalysts and advanced single-atom materials.In a study published in Chemical Science, a research team led by Prof. JIANG Ling and Prof. XIE Hua from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) revealed the competitive mechanism of dual-mode nitrogen fixation in negatively charged metal tricarbon cluster, MC₃⁻ (M = Os, Ir, Pt).Nitrogen fixation mechanism diagram of MC3– (M = Os, Ir, Pt) clusters (Image by DU Shihu)By combining photoelectron spectroscopy with quantum chemical calculations, researchers investigated the reactivityof MC3– clusters in activating nitrogen molecules. They demonstrated that these clusters exhibited two competing nitrogen activation pathways: cleavage of the N≡N triple bond with the formation of a stable C–N bond, and chemisorption of nitrogen onto the metal center. Among the studied clusters, OsC3− primarily facilitates N≡N bond cleavage, IrC3− displays the coexistence of dual nitrogen activation mechanisms, while PtC3− favors nitrogen fixation mainly through chemisorption.Further theoretical analysis revealed that the activation of nitrogen by MC3– decreases as the 5d orbital energy of the metal atoms lowers, while the predominance of chemisorption correspondingly increases."Our study provides molecular-level insightsinto dinitrogen activation by mononuclear metal carbide clusters and establishes a new paradigm for developing efficient catalysts for dinitrogen fixation," said Prof. XIE.