Due to exactly atomic composition and crystal structure, atomically precise copper nanoclusters are used as model catalysts for catalytic reaction mechanisms study. However, the efficient synthesis of copper nanoclusters still remains challenging.
　　Recently, a joint group led by Prof. HUANG Jiahui and Prof. FAN Hongjun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a new strategy for synthesis of atomically precise copper nanoclusters by solvent-mediated precipitation.
　　This study was published in Chemical Science on Dec. 20, 2022.
　　The total crystal structure and absorption optical spectrum of Cu13H10(SR)3(PPh3)7 nanoclusters (Image by LIN XinZhang)
　　"We named the new strategy as 'solvent-mediated precipitation synthesis (SMPS)', it was realized to efficiently synthesize Cu13H10(SR)3(PPh3)7 nanoclusters where SR was a thiolate ligand," said Prof. HUANG.
　　The copper nanoclusters, Cu13 for short, were prepared via precipitation, and the excess raw materials and by-products were remained in the solution, solving the problems of separation and low yield of Cu nanoclusters.
　　Single crystal X-ray diffraction analysis showed that the core of the Cu13 nanocluster with a triple axis of symmetry consists of four vertices-sharing tetrahedrons. Electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy confirmed the types and number of hydrogen atoms in Cu13 nanoclusters. Density functional theory calculations simulated the location of 10 hydrides in the crystal structure.
　　Moreover, steady-state ultraviolet-visible absorption and fluorescence spectra of Cu13 nanoclusters exhibited unique optical absorbance and photoluminescence.
　　"This study not only provides a novel SMPS strategy for the efficient synthesis of Cu13 nanoclusters, but also explains the relationship between the structure and optical properties of copper nanoclusters," said Prof. HUANG.
　　The work was supported by the National Natural Science Foundation.

Maintaining the protein high-order structures and interactions during the transition from aqueous solution to gas phase is essential to the structural analysis of native mass spectrometry (nMS).Recently, a research group led by Prof. WANG Fangjun from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. SHUN Feng from Southwest Jiaotong University, systematically interrogated the effects of charge state and crown ether complexation on the gas-phase native-like protein structure by integrating nMS with 193 nm ultraviolet photodissociation (UVPD). They have revealed the molecular mechanism of crown ether microsolvation effect on the gas-phase native-like protein structure.This study was published in Journal of the American Chemical Society on Dec. 30, 2022.nMS and UVPD exploration of the molecular details of the CE microsolvation effect on the native-like protein structure in the gas phase (Image by LIU Zheyi and ZHOU Lingqiang)The nMS is a cutting-edge technique for studying the composition and structure of proteins and their complexes. Non-denaturing electrospray ionization use biocompatible solutions to transfer proteins from liquid to gas phase while maintaining higher order structure and interactions.However, positive charged residues in protein will form hydrogen bonds with protein backbone carbonyls to stabilize the positive charges of the side chains through intramolecular solvation.Although the change of protein collision cross-sectional area caused by intramolecular solvation has been detected by ion mobility-mass spectrometry, there is still a lack of effective analytical means to accurately characterize the specific site where it occurs and the region that causes structural changes.In this work, the researchers applied the self-built nMS-UVPD platform and home-developed MS data process software to monitor the conformational changes induced by intramolecular solvation. Based on the UVPD fragmentation pattern of myoglobin-heme complex, they determined the detailed microsolvation sites and the regions with conformational changes.Then, they systematically characterized the protein structure alternations between protein ions with different charge states. They found that the gas phase structure of proteins in the high charge state was easily affected by the intramolecular solvation effect and deviated from the solution state structure, and the gas phase structure of low charge protein ions was closer to solution state.Furthermore, they proved that the complexation of the crown ether 18C6 with protein mainly occurred in solution, and then played an important role in stabilizing the protein structure during the electrospray ionization process.UVPD-nMS analysis revealed that the crown ether was mainly bound to protein region with high charge density, and the gas phase structure of the protein was closer to the solution state by blocking the intramolecular solvation of the charged side chain."This work demonstrates the significant advantages of UVPD-nMS in simultaneously obtaining protein sequence and dynamic structure information, and provides theoretical and technical insights for the maintenance and efficient characterization of protein solution structures in nMS," said Prof. WANG.

　　Polymers with their rich diversity, outstanding flexibility, and good processability can effectively enhance the functionality of supercapacitors (SCs) and expand their practical applications. Currently, polymer materials used in SCs are non-biodegradable, posing threats to the environment. 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 biodegradable polymers, a component of future green SCs.
　　Their review article was published in Advanced Functional Materials on Feb. 8.
　　Biodegradable polymers in supercapacitors and the recycling process (Image by WU Lu)
　　"A green SC requires good biodegradability of different components to achieve harmless disposal in various environments," said Prof. WU. "To meed these requirements, the device preparation must be highly dependent on the application of biodegradable polymers and innovative design strategies."
　　The researchers summarized the classification of existing biodegradable polymers and their typical structure, properties, and preparation processes, as well as the main applications of biodegradable polymers in different components of SCs, including electrodes, electrolytes, substrate, and encapsulation materials.
　　They also discussed the research progress of biodegradable polymer-based SCs in terms of preparation strategies and modification methods, as well as the key role of biodegradable polymers in the development process of green SCs.
　　Moreover, they briefly proposed the future perspectives and challenges faced by biodegradable polymer-based SCs.
　　"Biodegradable polymers are the ideal raw material, and suitable research strategies and preparation methods are powerful means to realize environment-friendly treatment of supercapacitors" said Prof. WU.
　　The above work was supported by the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.

　　The n-paraffin hydroisomerization catalyzed by bifunctional catalysts is an atom-economic reaction and one of the most important reactions in chemical industry.
　　Bifunctional catalyst used in this reaction contains an acid function and a noble metal function. The balance of these two functions is the key for the high catalytic performance. Without this balance, the isomerized carbonium ions formed on acid sites will undergo subsequent cracking, giving rise to light alkanes.
　　Recently, a research group led by Profs. TIAN Zhijian and WANG Congxin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has developed a new strategy to elevate the intrinsic property of metal function and prepared a highly-efficient PtCeOx/ZSM-22 catalyst for n-paraffin hydroisomerization reaction. They also revealed the structural feature of Pt, as well as the nature of the high intrinsic activity.
　　The study was published in Chem Catalysis on Jan. 26.
　　The electron transfer pathway and n-paraffin conversion scheme on the PtCeOX/ZSM-22 catalyst (Image by WANG Congxin)
　　The researchers proposed a facile sequential impregnation method by taking advantage of the discrepancy in point of zero charge between ZSM-22 support and ceria additive, through which the CeOx species were formed across the rod-like ZSM-22 support and Pt nano clusters were anchored on the surface of ceria.
　　They found the electron transfer between Pt and CeOx. This electron transfer effect brought a significant elevation for the intrinsic activity of the catalyst. It enabled Ptδ+ species to quickly activate C-H bonds in the initial dehydrogenation of alkanes step and donate the electron to saturate the branched alkenes in the terminal hydrogenation step of n-paraffin hydroisomerization process.
　　This catalyst (0.3wt%PtCeOx/ZSM-22) showed high performance in n-paraffin hydroisomerization with enhanced turnover frequency, a high isomer selectivity (96%) at high n-paraffin conversion rate (91%), and an 87% i-paraffin yield which was superior to the ever-reported commercial Pt/ZSM-22 catalyst with traditional high Pt content (no less than 0.5wt% Pt).
　　"This work provides not only new insights in Pt-metal oxide interaction in bifunctional catalysts, but also strategy for efficient bifunctional catalyst manufacture in potential industrial applications," said Prof. WANG.
　　The above work was supported by the National Key R&D Program of China, the Strategic Priority Research Program of CAS, and the Youth Innovation Promotion Association of CAS.

Per- and polyfluoroalkyl substances (PFASs), a class of chemicals, are featured with hydrophobicity, lipophobicity, and thermal stability. Since the 1950s, they have been widely used in a wide range of industrial and consumer products.However, PFASs' bioaccumulation and toxicity in wildlife and humans restrict their applications. Next-generation PFASs such as perfluoroether carboxylic acids (PFECAs) are needed to replace conventional PFASs. Nevertheless, information regarding their possible environmental and human health risks is limited.Recently, a research group led by Prof. XU Guowang from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. WANG Jianshe from Yantai University, revealed the toxic effects of PFECAs to mice.This study was published in Journal of Hazardous Materials on Jan. 20.Illustration of the toxic effects and the mechanism of PFO5DoDA in this study (Image by YANG Jun and Liu Xinyu)The researchers explored the effects of PFECAs on mice based on long-term exposure to environmentally relevant doses of perfluoro-3,5,7,9,11-pentaoxadodecanoic acid (PFO5DoDA), and revealed that PFECAs exposure suppressed many cellular stress signals and resulted in hepatomegaly.They found that PFO5DoDA acted as an agonist of the peroxisome proliferator-activated receptor (PPAR) in vitro and modulated PPAR-dependent gene expression in the liver. In addition, PFECAs had an inhibitory effect on the glucocorticoid receptor (GR), which might contribute to suppression of stress signals. GR suppression induced by PFECAs was not found in conventiperfluorooctanoic acid (PFOA).Through liver metabolomics analysis, the researchers found that PFO5DoDA-induced changes in both GR and PPAR signals remodeled hepatic metabolic profiles, including decreased fatty acids and amino acids and increased β-oxidation."Our work highlights the potential risk of PFECAs to human and wildlife health," said Dr. LIU Xinyu, corresponding author of this study.This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Youth Innovation Promotion Association of CAS.

Catalytic syngas conversion is the key route to bridge the gap between various carbon resources and essential chemicals. Oxide-zeolite (OXZEO) bifunctional catalysis is a new platform for this conversion, showing great potential for further industrialization.However, the in-depth understanding of the structure-activity relationship of the catalysts-reaction, especially on oxide component is still unclear.Recently, a research team led by Prof. HOU Guangjin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has revealed the synergistic interplay mechanism of dual active sites on bimetallic oxide for efficient syngas conversion at atomic level.This study was published in Chem on Feb. 8.Revealing the synergistic interplay of dual active sites on a spinel ZnAl2O4 bimetallic oxide for syngas conversion by state-of-the-art solid-state NMR technologies (Image by HAN Qiao and GAO Pan)The researchers investigated syngas conversion over a representative spinel ZnAl2O4 oxide with combined advanced solid-state nuclear magnetic resonance (NMR) technologies. They utilized in-situ NMR method to observe the full process of syngas conversion to methanol over ZnAl2O4 catalyst, during which the formate and methoxy species were identified as the key intermediates.Through a series of double resonance and multi-dimensional correlation NMR experiments, they identified the dual active sites with structure of -AlIV-OH···ZnIII-. Thus, they proposed the synergistic catalytic mechanism of the dual active sites on ZnAl2O4 catalyst for syngas conversion reaction.Moreover, they elaborated the dynamic evolution of the reaction intermediates and active sites during the reaction process at atomic level."On one hand, our work exemplifies the increasing capability of solid-state NMR spectroscopy in the study of surface/interface catalysis," Prof. HOU said. "On the other hand, the current understanding of the active sites and reaction mechanism can bring inspiration to study syngas conversion and CO2 hydrogenation on other bimetallic oxide systems, providing important guidance for the rational design and modulation of high-efficiency oxide catalysts."The study was supported by the National Key R&D Programme of China, the National Natural Science Foundation of China, the Liaoning Revitalization Talents Program, the China National Postdoctoral Program for Innovative Talents, the China Postdoctoral Science Foundation, and the DICP funding.