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.

Recently, Assoc. Prof. SHI Song from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. Dion Vlachos from the University of Delaware, have developed a new strategy for furfural conversion via hydrogen bond regulation.This study was published in Nature Communications on Jan. 26.Enzymes inspired microenvironment-controlled catalyst (Image by SHI Song)In biomass upgrading, the selective conversion of biomass-based substrates is always difficult due to the various functional groups.In this study, the researchers designed a porous organic framework-based catalyst. And inspired by enzyme catalysis in nature, they regulated the microenvironment of the active site by changing the functional groups over the porous organic framework. The change in the microenvironment could control the interaction between substrate and catalyst, improving the activity and selectivity of carbonyl-containing substrates such as furfural.They found that the nearby hydroxyl groups around the active site form hydrogen bonds with the carbonyl groups in the substrate, thereby changing the adsorption conformation of the substrate on the catalyst surface and realizing the activity and selectivity control of different substrates."The proposed synthetic strategy opens a new class of porous polymers for selective catalysis," said SHI.The above work was supported by the National Natural Science Foundation of China and the International Talent Program of DICP.

　　Prussian blue analogues (PBAs) are featured with high theoretical specific capacity, long cycle life, environmental benignity, and low cost. They are promising as cathode materials for sodium-ion batteries (SIBs). However, the working mechanism of PBAs is still unclear, hindering their applications.
　　Recently, a research team led by Prof. WANG Junhu from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS), in collaboration with Prof. LI Xianfeng from DICP and Dr. Moulay Tahar Sougrati from the University of Montpellier, revealed the charging/discharging mechanism and capacity degradation principle of Prussian blue cathode in SIBs through operando Mössbauer spectroscopy.
　　This study was published in Nano Energy on Feb.5.
　　Schematic diagram of HS/LS Fe redox mechanism and local structure changes in the electrochemical reaction process (Image by WANG Zinan)
　　The researchers synthesized a sodium-rich Prussian blue by co-precipitation method, and used it as a cathode for SIB. The prepared SIB showed good electrochemical performance, which could maintain 81% capacity retention after 980 cycles under 120 mA g-1.
　　Furthermore, they on-line observed the working process of the SIB through operando Mössbauer spectroscopy, and revealed the working mechanism of Prussian blue using low-temperature 77K 57Fe Mössbauer spectroscopy, operando X-ray diffraction spectroscopy, and synchrotron X-ray absorption spectroscopy combined with the operando Mössbauer spectroscopy.
　　They found that the reaction of high-spin (HS) Fe and low-spin (LS) Fe reacted stepwise. The HS Fe reacted completely and contributed to most capacity, while only part of LS Fe reacted. This was the main reason for the discrepancy between practical capacity and theoretical one.
　　However, they also found that LS Fe could lead to more severe local distortions with respect to the effects imposed by the same amount of HS Fe, which decreased cycling stability.
　　Therefore, the good cycling performance for the Prussian blue cathode material could be assigned to the tiny changes of crystal parameters and the incomplete reaction of LS Fe.
　　"This work provides new insight into developing of PBAs cathode materials with high capacity and good cycling stability," said Prof. WANG.
　　This work was supported by the National Natural Science Foundation of China, the International Partnership Program of CAS, the President's International Fellowship Initiative (PIFI) of CAS.