Synergism between B–N atomic pair for promoting the catalytic cracking of 1,2-dichloroethane†

The catalytic cracking of 1,2-dichloroethane (EDC) to obtain vinyl chloride (VCM) monomer is a crucial step in the production of polyvinyl chloride (PVC). The heteroatom-doped carbon catalysts have exhibited desired performance; however, the underlying mechanism is still not fully understood. Herein, a series of B–N co-doped carbon (BNC), N-doped carbon (NC), B-doped carbon (BC) and pure carbon (C) catalysts were prepared for EDC catalytic cracking, and the synergistic mechanism between B and N was carefully investigated. The BNC catalyst exhibits prominently higher activities with an EDC conversion of 53.9% at 250 °C. Through a combination of experimental and theoretical analyses, it is rationalized that the formation of the B–N atomic pair contributes to the enhanced performance and the electronic interaction between the B–N atomic pair imparts greater basicity to the N sites, which reduces the activation energy barrier for C–H bond cleavage by 0.34 eV. The present results provide a theoretical foundation for the precise design of highly efficient non-metallic carbon-based catalysts for EDC cracking.