A Hybrid Plasma-Catalysis System for CO2 Hydrogenation over Perovskite-Type Catalysts: Promoting Effect of A-Site Substitution

A hybrid dielectric barrier discharge (DBD) plasma-catalysis system is an effective way to catalyze the conversion of small molecules such as carbon dioxide. Until now, ABO(3) perovskite catalyst used for CO2 hydrogenation to light hydrocarbons reaction has been rarely reported. Herein, the lanthanum nickel perovskite-type catalysts named as La(0.8)A'0.2NiO3 +/-delta (A' represents for Ca, Ce, Pr, Sr) are prepared by a modified nitrate citric acid method, and the influence of A-site substitution on catalytic performance is investigated. The reactivity results show that the substitution of A-site can improve CO2 conversion and C2-4 (hydrocarbons containing C-2-C-4) selectivity in varying degrees. Compared to LaNiO3 catalyst, the La0.8Ca0.2NiO3 +/-delta catalyst has CO2 conversion increased from 72.6% to 82.3%, and C2-4 selectivity from 5.8% to 8.5%. The superior performance can be put down to the formation of smaller Ni particle size on La0.8Ca0.2NiO3 +/-delta catalyst, which promotes the activation of H-2. Additionally, the sufficient oxygen vacancies on La0.8Ca0.2NiO3 +/-delta provide more active sites for CO2 adsorption and then enhance CO2 conversion. The hybrid DBD plasma-catalysis system is proved effective for CO2 hydrogenation, and the idea of using A-site substitution would serve as a guide for the modification of perovskite-type ABO(3) catalysts.