Metallic cobalt-anchored carbon with non-metallic heteroatom decoration: Remarkably effective oxidative desulfurization catalyst

Abstract

The discovery of low-cost, highly effective, and novel catalytic materials for oxidative desulfurization (ODS) of liquid fuel is an important topic in the field of heterogeneous catalysis from both academic and industrial viewpoints. Different metallic active component supported on porous carbon was found as effective catalysts for ODS reactions and the contribution of the secondary or non-metallic heteroatom decoration on the carbon was also assumed. However, the precise role of the doped heteroatom(s) on boosting the ODS process is unknown. Here, a new approach to prepare a series of cobalt-anchored porous carbon (Co@C) with different heteroatom co-dopants (i.e., N, P, and B) and their effects on boosting oxidative desulfurization (ODS) from fuel were firstly instigated. The Co@nitroneneous carbons with P or B co-dopants could be derived via the carbonization of a bimetallic MOF with extra N, P, and B sources. A newly designed/developed Co@C catalyst exhibited high intrinsic activities in ODS. Importantly, Co@C having suitable N and P contents had an extremely low Ea (21 KJ·mol-1) and the highest TOF (104 h-1), among the studied/reported materials, for the oxidation of dibenzothiophene. We also firstly demonstrate the precise role of doped heteroatoms in Co@C in accelerating ODS by the synergy between doped heteroatoms and the reduction of the HOMO-LUMO energy gap of the catalyst. This approach can pave the way for tuning the catalytic performance through atom-level surface modification of carbonaceous catalysts.