Investigation on the key factors of MoP catalysts prepared by a carbothermal reduction method for dry reforming of methane

Abstract

The carbothermal reduction (CR) method for the synthesis of MoP catalysts has received much attention due to the increase of carbon materials as promising supports in various MoP-catalyzed reactions. In this work, we prepare three MoP catalysts (MoP-Glu, MoP-HMT and MoP-PFR) with different specific surface areas, particle sizes and surface carbon contents using the CR method, and give insights into the key factors of the MoP catalysts for dry (CO₂) reforming of methane (DRM). According to the redox mechanism on MoP, the key factors should be those which can influence the oxidation resistance ability (ORA) and methane dissociation ability (MDA) of MoP. It is found that the surface carbon content and particle size have main effects on the ORA and MDA of MoP, respectively. However, the specific surface area is not associated with any of them. The higher content of surface carbon can promote ORA and the MoP particles with a smaller size favor the increase of MDA. It was worth noting that excess surface carbon (oversized MoP particles) can weaken the MDA (ORA). Therefore, surface carbon content and particle size are proposed as the key factors of MoP prepared by the CR method for DRM. MoP-Glu with an appropriate surface carbon content and particle size showed a much higher catalytic stability than MoP-HMT and MoP-PFR.