Recently, the team of Deng Dehui, a researcher at the State Key Laboratory of Catalysis Fundamentals, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, successfully implemented electrocatalytic efficient decomposition of hydrogen sulfide to produce high-purity hydrogen, which provided new ideas for the elimination of hydrogen sulfide pollutants and the coupling of green hydrogen energy. Hydrogen sulfide is a toxic gas widely present in petrochemical industry, but it is also a potential raw material for hydrogen production. At present, the industry uses the Claus method to treat hydrogen sulfide, but only sulfur powder is recovered, and the hydrogen component is discharged in the form of water vapor, which cannot be effectively used. Electrocatalytic decomposition of hydrogen sulfide is a gentle and efficient method, which can produce hydrogen through the cathode and produce sulfur at the anode, while achieving the separation and recovery of hydrogen and sulfur powder. However, among the currently reported catalysts, precious metals are expensive, and transition metals and their oxides are easily poisoned or corroded by the reaction medium and lose their activity, which greatly limits the development of this technology. Therefore, it is urgent to develop a low-cost, excellent activity, corrosion-resistant catalytic material for the efficient electrocatalytic decomposition of hydrogen sulfide to produce hydrogen. The Deng Dehui team is based on the concept of armor catalysis that was first proposed internationally (Angew. Chem. Int. Ed., 2013, 52, 371; Angew. Chem. Int. Ed., 2014, 53, 7023; Energy Environ. Sci. , 2014, 7, 1919; Angew. Chem. Int. Ed., 2015, 54, 2100; Nature Nanotech., 2016, 11, 218; Energy Environ. Sci., 2016, 9, 123; Adv. Mater., 2017 , 29, 1606967; Adv. Mater., 2019, 31, 1901996), developed a new type of armor catalyst with graphene shell encapsulating cobalt nickel nanoparticles. The catalyst exhibits excellent catalytic activity and stability in the electrocatalytic hydrogen sulfide system. The optimized catalyst requires an initial potential of 1.24 V lower than that of electrolyzed water to produce hydrogen by electrolysis of hydrogen sulfide. At the same voltage, its current density can reach twice that of precious metal platinum-carbon catalysts, and much higher than other precious metals, metal oxides, carbon materials and other catalytic materials. This high activity did not decay in the 500h stability test, showing that the catalyst has good corrosion resistance. At the same time, the Faraday efficiency of cathode hydrogen production is as high as 98%, which realizes the efficient production of hydrogen. The team cooperated with Associate Professor Guan Jing of Qingdao University of Science and Technology and combined with theoretical calculations, it was found that the excellent activity of the catalyst stems from the synergistic modulation of the nitrogen structure of the metal core and the graphene shell on the electronic structure of the graphene shell, which promotes polysulfide The efficient generation of objects on the graphite surface. In order to confirm the reliability of the catalyst, the research team applied it to the demonstration experiment of removing and coupling hydrogen sulfide impurities (containing 2% hydrogen sulfide) in industrial syngas. In the stability test for up to 1200h, the catalyst It still maintains excellent stability, further confirming the great potential of the armor catalyst in the field of decomposing hydrogen sulfide to produce hydrogen. In addition, a large amount of sulfur ion pollutants are also present in the wastewater discharged from paper mills and leather factories. The armor catalyst is also expected to provide a new method for the electrocatalytic removal of sulfur ion pollutants in such wastewater. Related research results were published in the journal Energy & Environmental Science in the form of communication. The above research was funded by the National Key Research and Development Program of the Ministry of Science and Technology, the National Natural Science Foundation of China, the Frontier Science Key Research Project of the Chinese Academy of Sciences, the Collaborative Fund Project of the Clean Energy Innovation Institute of the Chinese Academy of Sciences, and the Collaborative Innovation Center for Energy Materials and Chemistry (2011 iChEM) of the Ministry of Education. Diamond Lapidary Grinder and Saw
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A new type of armor catalyst realizes electrocatalytic efficient decomposition of hydrogen sulfide to produce hydrogen