An efficient nanodiamond-based monolithic foam catalyst prepared by a facile thermal impregnation strategy for direct dehydrogenation of ethylbenzene to styrene  

作　　者：Guifang Ge Xiaojing Wei Hongchen Guo Zhongkui Zhao 

机构地区：[1]State Key Laboratory of Fine Chemicals,Department of Catalysis Chemistry and Engineering,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China

出　　处：《Chinese Chemical Letters》2023年第5期332-336,共5页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.21676046);the Chinese Ministry of Education via the Program for New Century Excellent Talents in Universities(No.NCET-12-0079)。

摘　　要：Nanodiamond(ND)has long been recognized as an effective carbocatalyst for synthesizing styrene via direct dehydrogenation(DDH).However,the induced drastic pressure drop of its powder form limits its industrial application in heterogeneous catalytic process.In this work,we report a facile hexamethylenetetramine nitrate(HN)-assisted thermal impregnation(HNTI)strategy for fabricating a novel nanodiamondbased monolithic foam(ND/CNT-SiC-ms-HN)catalyst through a two-step approach:One is to soak the carbon nanotube-modified Si C foam(CNT-SiC)with the slurry composed of HN,KCl,Li Cl,and dispersed ND,and the other is to heat the slurry-soaked CNT-SiC(ND-HN-KCl-Li Cl/CNT-SiC)in N_(2) atmosphere at750℃.The as-synthesized ND/CNT-SiC-ms-HN monolithic foam features the enriched surface kenotic C=O by promoted ND dispersion and O-doping,abundant stuctural defects,and improved nucleophilicity by N-doping,originating from the promoted ND dispersion by thermal impregnation(TI)in KCl-LiCl molten salt(MS)and the presence of HN in the annealing process.As a result,the ND/CNT-Si C-ms-HN monolithic foam catalyst by HNTI strategy exhibits 1.5 folds higher steady-state styrene rate(5.49 mmol g^(-1)h^(-1))associated with 98.4%of styrene selectivity compared to the ND-based monolithic foam catalyst(ND/CNT-SiC).Moreover,the ND/CNT-Si C-ms-HN monolithic foam shows excellent long-term stability for the direct dehydrogenation of ethylbenzene to styrene.This work also comes up with a novel way of preparing other highly-dispersed nanocarbons-based monolithic foam catalysts with promising catalytic performance for diverse transformations.

关 键 词：Nanodiamond-based monolithic foam Heterogeneous catalysis Thermal impregnation Ethylbenzene direct dehydrogenation Styrene production 

分 类 号：TQ241.21[化学工程—有机化工] TQ426