Construction of MoOx-C interface with two active sites by plasma for low-temperature reverse water-gas shift reaction

Abstract

The design and synthesis of robust catalysts is the key to improving CO₂ conversion in the reverse-water gas shift (RWGS). In this article, the MoO_x-C catalyst supported on AlOOH (xMoO_x-C@AOH) is designed and synthesized by dielectric barrier discharge (DBD) plasma. The Mo-C bonds of the MoO_x-C interface regulate the electronic structure of MoO_x and promote the formation of oxygen vacancies. The catalyst evaluation and reaction kinetics of the xMoO_x-C@AOH demonstrate excellent performance (CO₂ conversion 15.8% at 450°C) and superior selectivity toward CO (100%), without obvious deactivation within 100 h. The high activity of xMoO_x-C@AOH is related to two active sites: Mo sites of Mo-C are favorable for H₂ adsorption/dissociation; oxygen vacancies of MoO_x promote the adsorption/dissociation of CO₂. Two RWGS mechanisms are confirmed by DRIFTs: formate and direct CO₂ dissociation. This strategy of constructing the interface by DBD provides valuable insights to prepare high-performance catalysts for RWGS.