Effective Regulation Of The Structure And Properties Of Hybrid Perovskites Under Pressure?
Mar 07, 2022
The reporter learned from the University of Science and Technology of China that the research team of Professor Zeng Jie and Associate Professor Zhou Shiming of the Hefei National Research Center for Microscale Matter Science and the Department of Chemical Physics has developed a universal method for preparing single-atom catalysts by electrochemical deposition. , using this method, the researchers successfully prepared 34 kinds of single-atom catalysts, covering a variety of transition metals and a variety of substrates. The related results were recently published in Nature Communications.
Single-atom catalysts have attracted extensive attention in chemical reactions such as hydrolysis, oxygen reduction, carbon dioxide hydrogenation, and methane conversion due to their maximized atom utilization and unique electronic structure. However, the current methods for synthesizing single-atom catalysts have relatively high requirements on single atoms and substrates, and it is not possible to prepare any metal single-atom catalysts on any substrate. Adaptive single-atom synthesis methods are of great significance.
The researchers carried out electrochemical deposition under the electrochemical three-electrode system, and explored the effect of deposition conditions on the formation of single atoms, and found that when the metal loading is below a certain limit, single atoms can be obtained; Then there is the formation of metal clusters or particles, a change similar to the nucleation process in crystal growth in the liquid phase. In order to prove the universality of the method, the researchers successfully obtained single-atom catalysts covering 3d, 4d, and 5d metals on substrates such as cobalt hydroxide, molybdenum sulfide, manganese oxide, and nitrogen-doped carbon, and the prepared After the structural characterization of the single-atom catalyst, it was found that the same single-atom catalyst obtained by cathode and anode deposition has different electronic structures, which provides the possibility of its application in different catalytic reactions.
The experimental results show that some of the catalysts obtained by cathodic deposition show excellent performance in the electrocatalytic hydrogen evolution reaction. At the same time, some catalysts obtained by anodic deposition also showed good performance in the electrocatalytic oxygen evolution reaction. Electrochemical tests show that the system can achieve a full hydrolysis current density of 10 mA/cm2 with only a potential of 1.39 V, breaking the record for the lowest potential in alkaline electrolytes.
This universal approach not only injects new vitality into the field of single-atom catalysis, but also provides new ideas for systematically studying the relationship between catalyst structure and performance in the future.
