"Advanced Materials" reports new progress in micro -environment regulation under the conditions of Chinese acidic conditions

Recently, Professor Li Chunzhong of the School of Chemical Engineering and Jiang Hongliang's special researchers have made new progress in the study of micro -environment regulation of carbon dioxide catalytic interface under acidic conditions. Related results "Engineering Ni-N-C Catalyst Microenvironment Enabling Co2ElectroreDuction with Nearly 100% Co Selectivity in Acid" was published in "Advanced Materials".

The CO2 electro -catalytic reaction usually occurs in the alkaline/neutral flow pool, and there will be severe carbonate formation. In addition, the long -term electrolytic "water flooding" in the flow pool will cause the catalytic system. Unstable. In an acidic electrolyte, electrolytic CO2 can achieve high CO2 utilization and reduce the impact of carbonate deposition. However, the efficiency and stability of the system needs to be further improved, and the electrical catalysts and its working environment need to be regulated. This work can regulate the micro -environment of the electrocatalytic interface through the introduction of hydrophobic polytary ethylene (PTFE) in the gas diffusion electrode catalytic layer. Moderate PTFE modification can optimize the local CO2/H2O ratio in the catalytic layer, effectively inhibit acidity Under the conditions, the occurrence of hydrogen reactions (HER); at the same time, the thickness of the diffusion layer is reduced, forming a high-active and high-stable gas-liquid-solid three-phase interface micro environment.

Figure 1: Qi-liquid-solid three-phase interface to regulate the regulation of hydrophobicity on gas

In response to the electrical catalytic reduction process of CO2 gas, the work innovatively uses PTFE to regulate the hydrophilicity of the catalytic layer. Through electrochemical impedance analysis, the overall diffusion layer thickness and water of carbon dioxide and water are clarified. The quantitative matching relationship of ethylene content is calculated to calculate the optimized polytrafluoroethylene content (~ 60%mass score), and it is highly consistent with the electrocatalytic performance trend measured by the experiment. At the same time, the water anti -flooding capacity of the catalytic layer was studied, and the appropriate amount of polytrafluoroethylene (> 30%mass score) was added. In the process of industrial -grade current and long -term (greater than 500 hours), maintaining a good water resistance The flooding effect is used to maintain the stable gas-liquid-solid three-phase interface in the catalytic layer. The interface micro-environmental regulation strategy of the development of this work can be promoted to other electrochemical reactions involving gas-liquid-solid three-phase interface, such as nitrogen restoration, oxygen restoration, and other gaseous organic molecules in the aquatic solution.

The first author of the work was Sheng Xue, a master's degree, and the author of the communications was Professor Li Chunzhong and a special researcher Jiang Hongliang. In addition, the research work has received funding support for the integration project and key projects of the National Natural Science Foundation of China, the major projects of the Shanghai Science and Technology Commission, and the special professor (Oriental scholar) of the Shanghai University of Science and Technology.

Original link: https://onlineelibrary.wiley.com/doi/abs/10.1002/adma.202201295

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