In situ generated oxygen vacancy on Nb2O5 for boosted catalytic activities of M/Nb2O5 in photothermal CO2 reforming of CH4

Abstract

Photothermal synergistic CO2 reforming of CH4 (CRM) is a promising avenue to convert the greenhouse gases (CO2 and CH4) into valuable chemicals and store the abundant clean solar energy into chemical energy simultaneously. Developing photothermal catalysts that could drive CRM efficiently at low temperatures remains as a challenge. In the present study, Nb2O5 supported group VIII metal catalysts (M/Nb2O5) were synthesized, with the typical catalyst Rh/Nb2O5 recording a CO2 conversion rate of 50.6 mmol gRh−1 min−1 in CRM at 500 °C under visible light irradiation, about double fold higher than that achieved under the thermal-driven reaction condition. Mechanism study disclosed that oxygen vacancy was generated in situ over M/Nb2O5 under the CRM reaction atmosphere. The oxygen vacancy promoted CO2 adsorption and enhanced the light harvesting capacities of M/Nb2O5 catalysts, which ultimately boosted their activities in photothermal CRM. This study provides a promising pathway for the rational design of efficient catalysts by tailoring the properties of the catalysts under the reaction atmosphere.