Lead-free vacancy-ordered perovskite Cs2M4+X6 (X=Cl-, Br- or I-) nanocrystals have attracted much attention due to their low toxicity, high stability and unique optical properties.
　　In previously reported hot injection method for synthesizing perovskite nanocrystals, metal halides or metal acetates are often used as metal precursors. However, for many new perovskite nanocrystalline systems, the inability of these two types of metal salts to ionize in organic solvents is an important reason for synthesis failure.
　　Recently, a research group led by Prof. HAN Keli and Prof. YANG Bin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences discovered that metal acetylacetonates are a very suitable kind of metal precursors. By using Hf-based vacancy ordered perovskite as a model system and hafnium acetylacetonate as a metal source, they synthesized Cs2HfCl6 nanocrystals for the first time by hot injection method.
　　This study was published in Laser & Photonics Reviews on Dec. 13.
　　Different from previously reported perovskite nanocrystals, the newly-synthesized Cs2HfCl6 nanocrystal was a defect-intolerant semiconductor.
　　To mitigate the sub-band gap defect states inside Cs2HfCl6 nanocrystals, the researchers proposed a passivation strategy of Sb3+ doping, which had not been reported in previous perovskite studies.
　　Moreover, by using rare earth acetylacetonates, the researchers doped four rare earth ions, including Pr3+, Tb3+, Eu3+, Ho3+, into the crystal lattice of the Cs2HfCl6 nanocrystal host, and obtained tunable multicolor emissions.
　　Compared with the previously reported rare earth ions-doped perovskite nanocrystals systems, the use of rare earth acetylacetone compounds enabled rare earth element ions to be doped into the nanocrystals' lattice under a relatively milder temperature.
　　"Our study not only provides an effective strategy for regulating the optical properties of vacancy ordered perovskite nanocrystals, but also enriches the hot-injection synthesis method, which may promote the development of new perovskite nanocrystal systems," said Prof. HAN. (Text by YANG Bin and LIU Siping)

　　With the development of the internet of things and information technology, it can be foreseen that we will enter a digital, intelligent and fully connected world.
　　In the future, we may monitor our health status through wearable devices, cure diseases with the aid of advanced implanted microelectronics, and obtain real-time information about the surrounding environment by means of multi-node sensors, all of which require a large number of microscale electronic terminals as support.
　　Recently, a research team led by Prof. WU Zhong-Shuai from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) clarified the importance of digital microscale electrochemical energy storage devices, a component of microscale electronic systems.
　　This work was published as a Focus Review in ACS Energy Letters on Dec. 15.
　　Ideal construction process of digital microscale electrochemical energy storage devices (Image by SHI Xiaoyu and HOU Xiaocheng)
　　The researchers indicated that a fully connected and intelligent world required different electronic devices to possess highly designable and customizable properties, in order to achieve seamless integration and assimilation into various situations. Meanwhile, these requirements highly depended on the applicability of microscale electrochemical energy storage devices with the innovative all-around digitalization.
　　They summarized the current status and latest progress of digital microscale electrochemical energy storage devices from key materials, device geometries, structure engineering, fabrication process, functional characteristics and system integration. And they further discussed the respective design principles and promising development directions.
　　"It is a prerequisite to establish evaluation standards, and the enrichment of analysis methods and the introduction of machine learning technology are powerful means to realize the digitization of microscale electrochemical energy storage devices," said Prof. WU.
　　The researchers also proposed the future development direction and challenges of the digital microscale electrochemical energy storage devices in this work.
　　The above work was supported by the National Natural Science Foundation of China and the China Postdoctoral Science Foundation. (Text by SHI Xiaoyu and HOU Xiaocheng) 

　　In perovskite optoelectronic devices, the carrier mobility (or diffusivity) and diffusion length are fundamental properties that determine the performance of the devices.
　　However, limited by the small working space in a diamond anvil cell and the inside pressure transmitting media, the measurements of charge mobility and diffusion length in a diamond anvil cell are challenging by using traditional electrical techniques.
　　Recently, a research group led by Prof. JIN Shengye from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) revealed excellent carrier transport property of hybrid perovskites under high pressures.
　　This study was published in ACS Energy Letters on Dec. 8.
　　By combining time-resolved and PL-scanned imaging microscopy with a diamond anvil cell apparatus, the researchers in situ measured the photoinduced carrier transport in MAPbI3 perovskite microcrystals under high pressure up to 5.7 GPa, when the perovskites retained single crystal phase.
　　They found that the MAPbI3 microcrystals exhibited tetragonal-to-cubic phase transition at 0.3-0.4 GPa and isostructural phase transition at about 3 GPa as the pressure increased.
　　Moreover, through the direct examination of carrier transport dynamics in a diamond anvil cell, the researchers discovered that the diffusion coefficient of perovskites showed an increase by more than 30% when the pressure was over 0.4 GPa. Combining the corresponding carrier lifetimes, they found the carrier diffusion length (LD) was from 5 to 8 mm under different pressures.
　　This study suggested that the MAPbI3 perovskites could sustain their excellent carrier transport properties under pressure treatment, even though the pressure could cause significant structural defects to the crystal.
　　"This work sheds light on the influence of pressure on the carrier transport in MAPbI3 perovskites and paves the way for the utilization of compression to tune or optimize the optoelectronic properties of perovskites," said Prof. JIN.
　　This work was supported by the National Natural Science Foundation of China, the Ministry of Science and Technology of China, the Strategic Priority Research Program of CAS, and the Youth Innovation Promotion Association of CAS. (Text by YIN Yanfeng and TIAN Wenming)

　　The development of Cu-based catalysts is limited due to their poor thermal stability caused by the low Tammann temperature of Cu.
　　Recently, a research group led by Prof. YU Jiafeng and Prof. SUN Jian from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) constructed an ultra-highly stable Cu-based heterogeneous catalyst at high temperatures by constructing classical strong metal-support interactions (SMSIs).
　　This study was published in Nature Communications on Dec. 10. Prof. Noritatsu Tsubaki from Japan's Toyama University and Prof. LIU Yuefeng from DICP were also involved in this study.
　　Ultra-highly stable Cu/LaTiO2 heterogeneous catalyst at 800°C (Image by YU Jiafeng)
　　The researchers combined two unique technologies, magnetron sputtering (SP) and flame spray pyrolysis (FSP), to reconstruct the electronic structure of metallic Cu and the reducibility of the TiO2 support, respectively.
　　They created the classic SMSI on non-noble metal Cu-based catalyst at mild reduction temperatures for the first time, and realized controllable preparation of ultra-highly stable Cu-based catalyst. This catalyst exhibited ultra-stable performance for more than 500 hours at 600 °C. The sintering of Cu nanoparticles was effectively suppressed even at 800 °C.
　　Moreover, the strength of SMSI could be effectively controlled not only by reducing temperatures as before but also by tailor-made Cu via sputtering power regulation or decorated supports for rational catalyst design on demands.
　　"We expect that our new findings will serve as a general guide to design a highly stable heterogeneous catalyst at a wider temperature," said Prof. SUN.
　　This article was highlighted by the editors at Nature Communications as one of the most 50 exciting works published in "Catalysis" since May in 2021.
　　This work was supported by the National Natural Science Foundation of China and DICP. (Text by YU Jiafeng and SUN Jian)

　　Poly (1,4-cyclohexylene dimethylene terephthalate-co-isophthalate) (PCTA) is an important copolyester that has been widely used in cosmetic containers, home appliances, and medical packaging.
　　Currently, PCTA is manufactured via polycondensation of cyclohexanedimethanol (CHDM), which is industrially produced from petroleum-derived xylene. To reduce the reliance on fossil energy, it's needed to develop a more sustainable alternative way.
　　Recently, a research team led by Prof. ZHANG Tao, Prof. WANG Aiqin and Prof. LI Ning, in collaboration with Prof. WANG Feng's group, from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a sustainable route for the production of copolyester monomers with biomass.
　　This study was published in Angewandte Chemie International Edition on Nov. 30, and it was selected as Hot Paper.
　　A flow diagram for the production of monomers with acetaldehyde and acrylate (Image by YUAN Lin)
　　In this study, the researchers used plant-based acrylate and acetaldehyde as feedstocks, and produced PCTA monomer in an overall yield of 61%. The whole process included Morita–Baylis–Hillman (MBH) reaction, one-step dehydration/Diels–Alder reaction, and final Pd/C-catalyzed dehydrogenation.
　　Besides, they varied the final step to hydrogenation over Pd/C-Cu/Zn/Al dual-bed catalyst, and produced UNOXOLTM diol, which is another important monomer in coatings industry, in an overall yield of 67%.
　　Furthermore, the life cycle assessment implied that the newly-developed biomass-based routes had the potential to reduce carbon footprint.
　　"This study paves a new way for the production of renewable PCTA and also provides a new guidance for biomass conversion," said Prof. LI.
　　This work was supported by the Natural Science Foundation of China and Joint Fund of Yulin University and Dalian National Laboratory for Clean Energy. (Text by LIN Yuan and HU Yancheng)

　　Ethylene, as one of the most important building blocks in chemical synthesis, is mainly produced from naphtha cracking at high temperatures of around 800 ℃. Due to China is rich in coal and short of oil, it's importance to develop highly efficient ethylene production route from hydrogenation of coal-based acetylene.
　　However, traditional thermocatalytic hydrogenation of acetylene to ethylene (HAE) requires high temperatures and high pressure, leading to excessive energy consumption. Besides, large amount of H2 consumption makes this process even more costly.
　　Recently, a research group led by Prof. DENG Dehui from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) achieved a highly efficient electrocatalytic hydrogenation of acetylene to ethylene (E-HAE) under room temperature by directly using water as hydrogen source.
　　The study was published in Nature Communications on December 6.
　　The features of the E-HAE process compared with the traditional thermocatalytic HAE process (Image by WANG Suheng and YU Liang)
　　In contrast to the thermocatalytic path, the new process developed by the researchers was advantageous in being operatable under mild conditions and was environmental-friendly in combination with renewable energy-based electricity, in which hydrogen was in-situ generated from electroreduction of water so that extra supply of H2 could be avoided.
　　By optimizing the Cu catalyst to expose more active facets, preferential adsorption and hydrogenation of acetylene was facilitated against hydrogen adsorption and evolution. By using a microporous gas diffusion layer to promote mass transfer, a high Faradaic efficiency of 83.2% for ethylene production was achieved with a current density of 29 mA cm-2 at -0.6 V vs. RHE.
　　In-situ spectroscopic characterizations combined with density functional theory calculations demonstrated that electron transfer from the Cu surface to adsorbed acetylene promoted the adsorption and hydrogenation of the acetylene, while suppressing the competitive hydrogen evolution reaction and facilitating ethylene desorption, thereby resulting in highly selective ethylene production via the electron-coupled proton transfer pathways.
　　"This process provides a green route for industrial production of C2H4 from C2H2 under mild conditions," said Prof. DENG.
　　This work was supported by the National Natural Science Foundation of China, the Key Research Program of Frontier Sciences of the CAS, and Collaborative Innovation Center of Chemistry for Energy Materials (2011. iChEM). (Text by WANG Suheng and YU Liang)