Potassium-promoted single-atom Co-N-C catalyst for direct dehydrogenation of ethylbenzene  

作　　者：Jiajia Shi Yao Wei Leilei Zhang Dan Zhou Zhounan Yu Shengxin Zhang Xiaofeng Yang Ji Yang Yang Su Zheng Jiang Aiqin Wang 

机构地区：[1]CAS Key Laboratory of Science and Technology on Applied Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [4]Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201204,China [5]Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China

出　　处：《Nano Research》2023年第3期3687-3694,共8页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.22132006,21878289,and 22172159);CAS Project for Young Scientists in Basic Research(No.YSBR-022);the Youth Innovation Promotion Association CAS(No.2018216).

摘　　要：Alkali metals have been widely used as promoters of metal catalysts in various applications,yet the atomic understanding of the promotional mechanism remains elusive.In this work,we for the first time report the significant promotional effect of potassium to the Co-N-C single-atom catalyst for the direct dehydrogenation of ethylbenzene.K cation was introduced by impregnation of Co-N-C with KCl followed by calcination at 600℃,which resulted in the bonding of K to the Co-O moiety of the Co-N-C catalyst as revealed by X-ray absorption spectroscopy in combination with theoretical calculations.The formation of Co-O-K moiety led to the increase of electron density at the O atom due to electron transfer of K to O,and consequently facilitated the heterolytic cleavage of the C-H bond of ethylbenzene across the Co-O moiety.The promotional effect of K was found to be a volcanofunction with the K/Co ratio and became the greatest at the K/Co ratio of 1.36,which resulted in the highest steady-state reaction rate of 9.7 mmolEB·gcat^(−1)·h^(−1)reported thus far.Moreover,the catalyst exhibited excellent stability during 100 h time on stream.

关 键 词：alkali metal POTASSIUM promoter alkane dehydrogenation single-atom catalyst Co-N-C 

分 类 号：O64[理学—物理化学]