Confined catalysis has been regarded as an important strategy to modulate chemical reactions and enhance catalytic performance. Previous studies demonstrated that the applications of confinement effect in catalysis are in enclosed nanospace. However, whether an open space had this effect is still unclear.Recently, a research group led by Prof. BAO Xinhe and FU Qiang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) revealed the interface confinement effect on open space in In2O3-TiO2 catalyst during reverse water gas shift (RWGS) reaction. This study was published in the Journal of the American Chemical Society.Confinement-induced indium oxide nanolayers formed on TiO2 for enhanced CO2 hydrogenation reaction (Image by WANG Jianyang)The researchers physically mixed In2O3 and TiO2 to obtain an In2O3-TiO2 catalyst for the RWGS reaction. They verified that the open surface of TiO2 could create a confined environment for In2O3, which drove the spontaneous transformation of free In2O3 nanoparticles into In oxide nanolayers (InOx) covering onto the TiO2 surface during RWGS.Besides, the researchers found that the formed InOx nanolayers were easy to create surface oxygen vacancies but were against over reduction to metallic In in the H2-rich atmospheres, resulting in enhanced activity and stability compared with the pure In2O3 catalyst. They identified that the formation of interfacial In-O-Ti bonding drove the In2O3 dispersion and stabilized the metastable InOx layer.Therefore, the researchers demonstrated that the InOx overlayers with distinct chemistry from their free counterparts could be confined on various oxide surfaces, and the important confinement effect at oxide/oxide interfaces."The interface confinement effect plays an important role in many oxide/oxide catalysts, which can be used to enhance the catalytic performance," said Prof. FU.This work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, and the Photon Science Center for Carbon Neutrality.

　　Aqueous Zn batteries are considered as safe and low-cost alternatives to commercial Li-ion batteries.
　　However, water molecules in the aqueous electrolytes tend to undergo a phase transition from a disordered state to an ordered ice by forming extra hydrogen bonds. Furthermore, the electrostatic interaction between cations and anions in the electrolyte is strengthened at low temperatures, resulting in the undesired solidification of the aqueous electrolytes at low temperatures.
　　Consequently, the electrolyte freezing hampers the mobility of ions and impairs the low-temperature (particularly below -30 ℃) electrochemical activity of aqueous Zn batteries.
　　Recently, a research group led by Prof. WU Zhong-Shuai from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Sang-Young Lee from Yonsei University and Prof. Sang Kyu Kwak from Korea University, have developed a soft-acidic/hard-basic zwitterion for low-temperature anode-free Zn ion batteries. This study was published in Energy & Environmental Science.
　　Schematic depicting the roles of soft-acidic/hard-basic 2-(trimethylazaniumyl)acetate in enabling the low-temperature aqueous electrolyte and the cyclability of the anode-free Cu||Znxa-V2O5@Graphene pouch cell (115 × 95 mm2 in size) and its photograph (inset) (Image by WANG Xiao)
　　The researchers have proposed a new electrolyte design using zwitterions based on the hard and soft acids and based principle to restructure aqueous electrolytes.
　　They found that the incorporation of a soft-acidic/hard-basic zwitterion into an aqueous electrolyte could disrupt the hydrogen bonds of water molecules, weakening of zinc-trifluoromethanesulfonate (Zn2+ - OTf-) interactions, and resulting in the destabilization of the Zn2+ solvation sheath. Therefore, this electrolyte could enhance the anti-freezing phenomena with a solid–liquid transition temperature of -95 ℃ and Zn2+ desolvation kinetics.
　　By using this electrolyte, the researchers developed an anode-free full cell (Cu||Znxa-V2O5@graphene) which exhibited high energy and power densities (142 W h kg-1 at 50 mA g-1 and 230 W kg-1 at 2 A g-1) with stable cyclability at -40 ℃. It was comparable to low-temperature Li–metal batteries.
　　The above study was supported by the National Natural Sciences Foundation of China, and the DICP Innovation Foundation.

　　Chemical reactions are usually accompanied by thermal effects, inevitably resulting in temperature change in the reaction system. Therefore, temperature is an important parameter in reactions, which can affect chemical thermodynamics and reaction kinetics.
　　Precise measurement of the temperature near or at active sites inside a single catalyst particle during catalysis is important for establishing the reaction mechanism and developing the microscopic reaction kinetics.
　　Recently, a research team led by Prof. YE Mao and Prof. LIU Zhongmin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a three-dimensional spatiotemporal-resolved technique for the measurement of temperature distribution inside a single industrial zeolite-catalyst particle.
　　This study was published in the Journal of the American Chemical Society on Feb. 9.
　　Confocal up-conversion luminescence technique for the spatiotemporal measurements of temperature within individual catalyst particles (Image by GAO Mingbin)
　　The size of zeolite catalyst particles used in typical industrial processes is generally tens to hundreds of microns. However, the currently used thermocouples and infrared thermal imaging can only measure the surface temperature of the catalyst, and the spatial resolution is in millimeters.
　　To solve this problem, the researchers developed an imaging method with a spatial resolution of 800 nm, realizing the dynamic measurement of the three-dimensional spatiotemporal distribution of temperature inside the industrial zeolite catalyst particle during the methanol-to-olefins (MTO) reactions.
　　They developed this up-conversion confocal microscopic imaging technique by implanting the up-conversion nano-thermometer with high-temperature resistance into industrial zeolite catalyst particles using a microfluidic chip.
　　Furthermore, the researchers developed multimodal imaging techniques, i.e., confocal fluorescence and confocal infrared microscopy, and investigated the effects of zeolite contents and particle size on the spatiotemporal distribution of temperature inside the catalyst particles. They have revealed the utilization of active sites and the evolutions of reaction intermediates during MTO reactions affected by heterogeneous temperature distribution.
　　"This technique provides a new path to understand the heat transfer in catalyst particles toward rational design and optimization of industrial catalysts and catalysis," said Prof. YE.
　　This work was supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of CAS.

　　Converting carbon dioxide (CO2) from industrial point sources to chemicals and fuels utilizing renewable energy can help to tackle the climate crisis. CO2 electrolysis is one of the promising route. 
　　Previous studies were generally performed with pure or highly concentrated CO2 feeds, while the CO2 concentration in flue gas from the combustion of fossil fuels was very low, typically from 5% to 15%. The energy and capital costs associated with capturing and purifying CO2 from flue gas point sources are very high. The direct utilization of industrial flue gas bypassing the capture and purification steps for producing pure CO2 feeds is still challenging.
　　Recently, a research team led by Profs. WANG Guoxiong and GAO Dunfeng from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. AN Qingda from the Dalian Polytechnic University, have proposed a molecular enhancement strategy for direct electrolysis of dilute CO2 to CO.
　　This study was published in ACS Energy Letters on Feb. 9.
　　Molecularly enhanced direct electrolysis of dilute CO2 to CO (Image by CHEN Bingyu)
　　To deal with the unfavorable mass transport, reaction thermodynamics, and kinetics of direct electrolysis of dilute CO2, the researchers constructed reaction microenvironment surrounding catalytically active sites by molecularly modifying CoPc electrodes with a poly(4-vinylpyridine) (P4VP) molecule. The formed reaction microenvironment effectively integrated the capture and conversion of CO2 from dilute feed streams.
　　With a home-made alkaline membrane electrode assembly (MEA) electrolyzer, the researchers obtained a remarkable CO partial current density of 252 mA cm-2 with a CO Faradaic efficiency of 90% under the dilute feed with a typical CO2 concentration (10%) in flue gas, which was 2.24-fold higher than that of bare CoPc electrode.
　　Physicochemical and electrochemical structural characterization results indicated that the abundant pyridine groups of the P4VP modifier improved sequentially the physical adsorption and chemical activation of CO2 over Co sites of CoPc catalysts, resulting in the impressive performance for direct electrolysis of dilute CO2 to CO. 
　　This molecular enhancement strategy, with further precise control in catalyst structures and reaction microenvironments, will hold great promise in the direct electrolysis of industrial flue gas and the selective production of multicarbon chemicals such as ethylene.
　　"This work highlights the great promise of the molecular enhancement strategy for direct utilization of dilute CO2 stream from industrial flue gas," said Prof. GAO.
　　The above work was supported by the National Key R&D Program of China, the National Natural Science Foundation of China, the Collaborative Innovation Center of Chemistry for Energy Materials, the Liaoning Revitalization Talents Program, and the Youth Innovation Fund of DICP.

　　Ammonia is essential for food and future energy supply. In the industry, it is mainly produced by the Haber-Bosch process, which operates at high temperatures and pressures.
　　Due to the ammonia industry's high energy consumption and carbon emissions, it is important to develop alternative materials and approaches for efficient N2 reduction to ammonia driven by renewable energy.
　　Recently, a research group led by Prof. CHEN Ping from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has realized photo-driven nitrogen fixation and ammonia synthesis mediated by lithium hydride (LiH).
　　This study was published in Nature Chemistry on Jan. 16.
　　LiH is the simplest saline hydride with a band gap of 3.7 eV. It has been investigated for hydrogen storage due to its high hydrogen content (12.5 wt%). However, the dehydrogenation of LiH is thermodynamically unfavorable.
　　In this study, the researchers found that ultraviolet (UV) illumination of LiH could induce a notable color change from white to light blue, accompanied by the release of a small amount of H2 under ambient conditions. Such a phenomenon implied that under UV illumination, LiH underwent photolysis resulting in photon-generated electrons trapped in its hydrogen vacancy as long-lived and electron-rich F centers, which showed a fundamentally different mechanism for charge carrier separation.
　　Schematics for the photo-driven nitrogen fixation process of LiH and the photocatalytic ammonia synthesis performance (Image by GUAN Yeqin)
　　The researchers indicated that illuminated LiH had an electron-rich surface with hydrogen vacancies, which facilitated the activation of N2 to form N-H bond. Moreover, the researchers co-fed a N2/H2 mixture with a low H2 partial pressure into the LiH powders, leading to photo-catalytic ammonia production under ambient conditions.
　　"This photochemical route is flexibility in operation, which may be amenable to the small-scale and distributed ammonia synthesis powered by intermittent solar energy," said Prof. CHEN.
　　This work was supported by the Ministry of Science and Technology of China, the National Natural Science Foundation of China, and the Youth Innovation Promotion Association of CAS.

　　Recently, a team led by Prof. WU Zhong-Shuai has developed novel 2D atomically thin (001)-oriented single-crystalline LiCoO2 nanosheets with longer Li+ intercalation distance and (001) planes dominated surface for high-performance battery-supercapacitor hybrid devices.
　　This study was published in ACS Energy Letters on Jan 5.
　　Shorter Li+ intercalation distance or lower intercalation energy barrier enables fast diffusion in Li+ intercalation process. However, it is found that nanosize effect in nanocrystalline LiCoO2 affects surface-redox and Li+ intercalation processes simultaneously.
　　As the crystallite size decreases, more Li+ intercalation processes are replaced by surface-redox processes, which brings about decreased platform capacity, low initial coulombic efficiency, and poor cycle performance. Therefore, the nanosize effect restricted the application of nanostructured LiCoO2 in "double high" battery-supercapacitor hybrid devices.
　　To solve the above problem, Prof. WU's team attempted to regulate the nanosize effect by precisely controlling the Li+ intercalation process and surface-redox process.
　　They synthesized micro-sized atomically thin single-crystalline LCO nanosheets (SC-LCO) and nanocrystalline LCO nanosheets (NC-LCO). Compared with NC-LCO, SC-LCO presented longer Li+ intercalation distance and decreased side reactions.
　　They have found that both coulombic efficiency and discharge capacity of SC-LCO at 1C (194 mAh g-1, 92%) were higher than NC-LCO (173 mAh g-1, 86%). The specific capacity of SC-LCO maintained 151 mAh g-1 (83%) after cycling for 500 cycles, which preceded NC-LCO (84 mAh g-1, 63%).
　　Moreover, the researchers fabricated a battery-supercapacitor hybrid device with SC-LCO and achieved high-energy and high-power, demonstrating the practical applicability of this nanosheets.
　　The above study was supported by the National Natural Sciences Foundation of China, the DICP Innovation Foundation.