Years of in situ investigation by Mars landers and rovers, plus analysis of Martian meteorites, have shown that oxychlorine species are ubiquitous on the Martian surface.
　　Two stable phases, perchlorate (ClO4-) and chlorate (ClO3-), are suggested in the samples where oxychlorine species are detected. However, the factors that control the ClO4-/ClO3- generation ratios are not well understood.
　　Recently, Dr. ZHAO Yuyan’s group from the Institute of Geochemistry of Chinese Academy of Sciences (CAS), in collaboration with Prof. WANG Junhu’s group from the Dalian Institute of Chemical Physics (DICP) of CAS, evaluated the influence of secondary iron minerals on the production of ClO4- and ClO3- on Mars.
　　This study was published in Nature Astronomy on Feb. 7.
　　The conceptual model for ClO3-/ClO4-generation ratios via UV and O3 oxidation in different surficial environments on Mars (Image by ZHAO Yuyan)
　　The ClO4-/ClO3- abundance ratio is critical for the redox conditions, aqueous environments, and habitability on Mars due to their different physical and chemical characteristics.
　　The researchers found that Fe secondary mineralogy was the dominant factor controlling the ClO4-/ClO3- generation ratio: Fe sulfates and Fe3+-montmorillonite mixed with NaCl produced much higher yields of ClO4- than of ClO3-, whereas the opposite was true for NaCl-Fe (hydr)oxide mixtures.
　　Mössbauer spectroscopy results indicated that akageneite decomposed under oxidative conditions when exposed to UV or ozone and formed a set of mixtures of akageneite, goethite, hematite, and an inferred Fe-(hydr)oxide phase. The released chloride would be catalyzed to form oxychlorine species dominated by chlorate by the mineral assemblage.
　　The study further indicated that the physical state of chloride (Cl-) and the characteristics of the co-occurring minerals had the most significant influence. In contrast, oxidation sources and atmospheric composition induced only secondary effects.
　　"This study highlighted ClO4-/ClO3- generation ratios in different surficial environments relevant to Mars," said Dr. ZHAO. "ClO3- rather than ClO4- should be the key focus of future oxychlorine-related studies for Mars, including the redox environment, habitability, in situ organic analysis, and in situ resource utilization on Mars."
　　This study was supported by Strategic Priority Program of CAS, the National Natural Science Foundation of China, Civil Aerospace Technology Pre-research Program, the International Partnership Program of CAS. (Text by ZHAO Yuyan)

　　Strong Metal-Support Interaction (SMSI) effect, which often happens upon thermal treatment of supported metal catalysts at high temperatures, is important in heterogeneous catalysis. It is usually used to explain the morphology evolution and catalytic mechanism at the interfaces between metal and active oxide supports.
　　Recently, a research team led by Prof. FU Qiang and Prof. BAO Xinhe from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) found that SMSI state can be constructed in a Ru-MoO3 catalyst by CO2 hydrogenation reaction gas and at low temperature of 250°C, which favors the selective CO2 hydrogenation to CO.
　　This work was published in Journal of the American Chemical Society on March 8.
　　Overturning CO2 hydrogenation selectivity with high activity via reaction-induced strong metal–support interactions (Image by XIN Hui
　　The researchers evaluated the mixed metal oxide catalyst, 1.9 wt% Ru-Mo-Ox, in CO2 hydrogenation reaction without pre-reduction. They found that during the reaction, Ru nanoparticles facilitated the reduction of MoO3 to generate active MoO3-x overlayers due to H-spillover, and migrated onto Ru nanoparticles and formed the encapsulated structure of Ru@MoO3-x.
　　The formed SMSI state changed 100% CH4 selectivity on the fresh Ru particle surfaces to above 99.0% CO selectivity with excellent activity. The encapsulating oxide layers could be removed via O2 treatment, switching back completely to the methanation reaction. Moreover, they found that the interface confinement between encapsulating Mo oxide overlayers and Ru nanoparticles could stabilize the defective
　　This work suggests that the encapsulation of metal nanocatalysts can be dynamically generated in real reactions which helps to gain the target products with high activity.
　　This work was supported by National Natural Science Foundation of China, Strategic Priority Research Program of CAS, Liaoning Revitalization Talents Program, and the Dalian National Laboratory for Clean Energy Cooperation Fund. (Text by XIN Hui)

　　Molecular sieve membrane-based separation technology, featured with low energy consumption and small carbon footprint, has attracted much attention in gas separation.
　　Metal-organic frameworks (MOFs) are promising in gas separation membranes due to their diversified structures, high porosity and tailored functionalities. However, defect-free MOF membrane fabrication still remains challenging.
　　Recently, a research group led by Prof. Yang Weishen and Dr. PENG Yuan from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) has fabricated flexible soft-solid MOF composite membrane on commercial polyvinylidene fluoride (PVDF) substrate.
　　Within the membrane structure, the quasi-vertically oriented, solid Zn2(Benzimidazolate)4 particles grown on PVDF substrate provided predominant molecular sieving gas entrances while soft polyamide eliminated defects enclosing MOF particles, resulting in better performance in H2/CO2 separation.
　　This work was published in Angew. Chem. Int. Ed. on Feb. 1. It was selected as "Very Important Paper" for achieving high approvals from referees. "Less than 5% of our manuscripts receive such a positive evaluation," said the Editor.
　　Schematic illustrations of the flexible Zn2(Bim)4 SSCM structure (left) and H2/CO2 separation mechanism through the membrane (right) (Image by SHU Lun)
　　This robust defect-free composite membrane exhibited an outstanding anti-swelling capacity in condensable feedstock. It showed superior separation accuracies for large C2H6 and C3H8 exclusions.
　　Moreover, the researchers prepared the Zn2(Bim)4 composite membrane with an ultra-high MOF loading and excellent flexibility. After membrane folding and unfolding at 90° for 50 consecutive times or rolling into a tube with a diameter of 3 mm (the largest bending curvature that MOF membranes can endure), the membrane separation performance remained exactly the same.
　　Soft-solid Zero Insertion Force(ZIF)-67 and ZIF-8 composite membrane series were also fabricated. Taking advantages of defect elimination, the intrinsic molecular sieving capacities of the MOF particles were given full play.
　　"The facile fabrication approach benefits industrialized membrane scaling-up. And feasible membranes for specific separation systems can be customized by MOF and polymer modular design strategy," said Prof. YANG.
　　This work was supported by the National Natural Science Foundation of China. (Text by PENG Yuan)

　　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. CHENG Huiming from the Institute of metal research of CAS, developed high-voltage aqueous MXene planar micro-supercapacitors (MSCs) with wide temperature range based on water-in-LiCl (WIL) salt electrolyte.
　　This study was published in National Science Review on Feb. 23.
　　MXenes, a family of 2D transition metal carbides and nitrides with over 30 species, are emerging as high-performance electrode materials. However, MXene electrode is easily oxidized at high anodic potential in aqueous electrolytes, and its operating voltage is normally limited by the electrochemical thermodynamic stability window of water.
　　In addition, aqueous electrolytes freeze easily at sub-zero temperatures, leading to a sharp decline in ionic conductivity. While, at high temperatures, the structure of aqueous electrolytes is so unstable that it is difficult to retain internal water molecules because of volatility.
　　Characteristics of WIL electrolytes and flexibility and integration characterization of MXene-MSC-3.2 (Image by ZHU Yuanyuan, and ZHENG Shuanghao)
　　"We developed a low-cost and environment-friendly WIL salt electrolyte to regulate reaction kinetics of MXene (Ti3C2Tx) electrode and electrolyte, which not only broadened the operation voltage of MXene-MSCs by inhibiting oxidation at high potential, but also increased the temperature range owing to a low freezing point," said Prof. WU.
　　The as-fabricated symmetric planar aqueous MXene-MSCs with the above-mentioned electrolyte achieved an operating voltage of up to 1.6 V, and energy density of up to 31.7 mWh cm-3 at room temperature.
　　The low freezing point (-57 °C) of WIL gel electrolyte also enabled MXene-MSCs to operate stably in a wide temperature range (-40°C to 60°C). The scalability and flexibility of MXene-MSCs made it easy for them to be integrated into wearable microelectronics.
　　This work was supported by National Natural Science Foundation of China, Dalian National Laboratory for Clean Energy of CAS. (Text by ZHU Yuanyuan and ZHENG Shuanghao)

　　Zeolites are widely used in adsorption separation, ion exchange, and heterogeneous catalysis.
　　The site of acidity-related aluminum atoms in the zeolite framework is critical for the physicochemical performances of the zeolite.
　　Recently, a research team led by Profs. LIU Zhongmin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a new strategy to control the site of Al atoms in zeolite framework.
　　This study was published in Angewandte Chemie International Edition on Feb. 22.
　　a) Sketch map of a typical treatment process, showing the directional migration of framework Al into T3 sites of the MOR zeolite via LPST; b) The topology of MOR and the steric configuration of SiCl4and AlCl3 molecules with a kinetic diameter of 7.0 and 6.7 ？, respectively (Image by LIU Rongsheng)
　　In the strategy, the researchers relocated mordenite (MOR) framework Al atoms into the desired T3 sites by low-pressure SiCl4 treatment (LPST). The prepared MOR catalysts showed good catalytic performance in dimethyl ether carbonylation to methyl acetate reaction.
　　Furthermore, they investigated the change of framework compositions for the samples before and after LPST. They found that there were three stages during the treated reaction: Al extraction stage, Al migration stage and Al Insertion stage.
　　In Al extraction stage, due to the restriction of molecular size, SiCl4 could selectively access 12-membered ring (MR) rather than 8-MR channels. As SiCl4 molecules diffused into the 12-MR, they preferentially reacted with the framework Al in 12-MR with the release of AlCl3. That is to say, the undesired framework Al was extracted as a form of AlCl3 via replacing by Si.
　　As for Al migration stage, the AlCl3 molecule, which was more easily distorted owing to its plane triangle configuration, could migrate into 8-MR channels through the side pockets.
　　In Al Insertion stage, the AlCl3 could react with silanol defects of 8-MR channels to insert Al into T3 sites as tetrahedrally coordinated species.
　　Moreover, they used high-field 27Al nuclear magnetic resonance to identify the exact location of framework Al for the MOR samples. The results indicated that 73% of the framework Al atoms were at the T3 sites after LPST under optimal conditions, forming reactively favorable active sites (about 90%) in 8-MR channels. Therefore, it could controllably generate and intensify active sites in MOR zeolite for dimethyl ether (DME) carbonylation reaction with higher methyl acetate (MA) selectivity and much longer lifetime.
　　"This work puts forward a facile strategy for directionally relocating framework Al among the different T-sites of the MOR zeolite and potentially applicating it in other zeolites to control Al location," said Prof. LIU.
　　This work was supported by the National Natural Science Foundation of China, the International Partnership Program of CAS, the Key Research Program of Frontier Sciences of CAS. (Text by LIU Rongsheng)

　　The world's first demonstration device for 1,000 tons/year production of gasoline from carbon dioxide (CO2) hydrogenation located in Zoucheng Industrial Park, Shandong province, China has completed its trial operation and technology assessment on March 4.
　　The project was jointly developed by the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) and Zhuhai Futian Energy Technology Co., Ltd.
　　Pilot plant for the production of 1000 tons/year gasoline from carbon dioxide (CO2) hydrogenation (Image by HOU Shoufu)
　　Hydrogenation of CO2 into liquid fuels and chemicals can not only realize the resource utilization of CO2, but also facilitate the storage and transportation of renewable energy.
　　However, the activation and selective conversion of CO2 are challenging. A technology that can selectively produce value-added hydrocarbon fuels with high energy density will provide a new route for promoting clean and low-carbon energy revolution.
　　The technology of carbon dioxide hydrogenation to gasoline was proposed by SUN Jian, GE Qingjie and WEI Jian from DICP in 2017, with a paper published in Nature Communications.
　　The demonstration device has been completed in Zoucheng Industrial Park, in 2020. In October 2021, the device passed the continuous 72-hour on-site assessment organized by China Petroleum and Chemical Industry Federation (CPCIF). It could realize both CO2 and H2 conversion of 95%, gasoline selectivity of 85% in all carbon-based products, with reduced consumption of the raw material of CO2 and H2.
　　It produced clean and green gasoline product with octane number more than 90 conforming to the Chinese national VI standard, accompanied by low energy consumption of the whole process.
　　"This technology marks a new stage of CO2 resource utilization technology in the world, and provides a new strategy for realizing the goal of carbon neutral," said Prof. SUN.
　　This work was supported by the Strategic Priority Research Program of "Key Technologies and Demonstration of Transformative Clean Energy" of CAS, the National Natural Science Foundation of China, and the Liaoning Talents Program. (Image by SUN Jian, GE Qingjie and WEI Jian)