Low temperature catalytic reverse water-gas shift reaction over perovskite catalysts in DBD plasma

Abstract

With the aim of eliminating the serious environmental concern arising from excessive anthropogenic CO2 emission, a hybrid dielectric barrier discharge plasma-catalysis system was developed for the thermodynamic unfavorable reverse water-gas shift reaction at low temperature of < 150 °C. A series of perovskite catalysts including LaNiO3, La0.9Sr0.1NiO3+δ, La0.9Sr0.1FeO3+δ and La0.9Sr0.1Ni0.5Fe0.5O3+δ were synthesized, as well as the impregnated Ni/La2O3 as a reference. Among, La0.9Sr0.1Ni0.5Fe0.5O3+δ exhibited the highest potential in promoting the selective conversion of CO2 to CO, and simultaneously suppressing the formation of CH4. Its superior catalytic performance should be attributed to that (1) higher metal dispersion, smaller particle size, stronger metal-support interaction and electronically richer state of Ni were achieved by the formation of Ni-Fe alloy, which facilitated the adsorption and conversion of CO2, and (2) more oxygen vacancies and higher oxygen mobility were created by the remaining La0.9Sr0.1FeO3+δ perovskite structure, which promoted the selective conversion of CO2 to CO.