P-modified microporous carbon nanospheres for direct propane dehydrogenation reactions

Abstract

In this work, a variety of microporous carbon nanospheres (MCNs) were synthesized by the in-situ approach, and used as metal-free catalysts for direct propane dehydrogenation (DPDH). Pristine MCNs showed excellent catalytic performances for DPDH with initial propane conversion of 26% and propylene selectivity of 87%–88%. Phosphorus (P) modifications with different P sources put different effects on the catalytic performances of MCNs in DPDH, i.e., triethyl phosphate exhibited a positive, while (NH4)2HPO4 and H3PO4 showed a negative effect on the catalytic performances for the in-situ doping carbon catalysts. The amount of surface oxygenic groups and the graphitization extent of carbon materials are two important factors influencing the catalytic performances of MCNs in DPDH. These results indicate that P modification is an effective way to adjust the catalytic performances of MCNs in DPDH. While, except the dopant itself, the interaction between the dopant and other materials during the synthesis process also influences the surface oxygenic groups and the graphitization degree of carbon materials.