Dang Kun, Dong Hongliang, Wang Ligang, Jiang Mai, Jiang Sen, Sun Wenming, Wang Dingsheng, Tian Yang
Department of Chemistry, Analytical Instrumentation Center, Capital Normal University, Beijing, 100048, P. R. China.
Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, P. R. China.
Adv Mater. 2022 Jul;34(27):e2200302. doi: 10.1002/adma.202200302. Epub 2022 May 27.
Electrocatalytic oxidation of organics using water as the oxygen source is a prospective but challenging method to produce high-value-added chemicals; especially, the competitive oxygen evolution reaction (OER) limits its efficiency. Herein, a tandem catalysis strategy based on a single-atom catalyst with Cr atoms atomically dispersed at a CoSe support (Cr /CoSe ) is presented. Thereinto, Co and Cr sites are endowed with a specific function to activate water and styrene respectively, and the competition between the OER and styrene oxidation is turned into mutual benefits via cooperated active sites. Under a potential of 1.6 V , excellent selectivity of 95% to benzaldehyde and a high conversion rate of styrene at 88% without any exogenous oxidizing reagent are achieved. Isotopic tracing, isotope-labeled in situ Raman spectra, and detailed theoretical calculation further reveal the tandem mechanism, showing that the transfer of *OOH intermediates from the Co to the Cr sites serves as a bridge to link the oxidation of water and styrene. This work develops a new strategy for the co-oxidation of multi-species based on tandem catalysis, providing novel insights for the design of single-atom catalysts.
以水为氧源对有机物进行电催化氧化是一种制备高附加值化学品的有前景但具有挑战性的方法；特别是，竞争性析氧反应（OER）限制了其效率。在此，提出了一种基于单原子催化剂的串联催化策略，其中Cr原子以原子方式分散在CoSe载体（Cr/CoSe）上。其中，Co和Cr位点分别具有活化水和苯乙烯的特定功能，并且通过协同活性位点将OER与苯乙烯氧化之间的竞争转化为互利。在1.6 V的电位下，在没有任何外源氧化剂的情况下，实现了对苯甲醛95%的优异选择性和88%的苯乙烯高转化率。同位素示踪、同位素标记原位拉曼光谱和详细的理论计算进一步揭示了串联机制，表明*OOH中间体从Co位点向Cr位点的转移充当了连接水和苯乙烯氧化的桥梁。这项工作开发了一种基于串联催化的多物种共氧化新策略，为单原子催化剂的设计提供了新的见解。
