Effect of Ca on Perovskite La_1−xCa_xNiO₃ Catalyst for CO₂ Hydrogenation‐to‐Light Hydrocarbons in a Dielectric Barrier Discharge Plasma Reactor

Abstract

Herein, the effects of the incorporation amount of Ca on the formation of C2–C4 in the hydrogenation of CO2‐to‐light hydrocarbons are studied in a hybrid dielectric barrier discharge–perovskite catalysis system. A series of La1−xCaxNiO3 (x = 0.1, 0.2, 0.3, 0.4) catalysts are prepared by a modified nitrate citric acid method. The catalysts are characterized by Brunauer−Emmett−Teller, X‐ray diffraction, transmission electron microscopy, H2‐temperature‐programmed reduction, CO2‐temperature‐programmed desorption, and X‐ray photoelectron spectroscopy. The results shows that NiO is dissolved on the catalyst surface after calcination, while NiO size increases with the rise of Ca amount. Meanwhile, different degrees of crystal defects are formed in La1−xCaxNiO3, leading to change of specific surface area, adsorbed oxygen amount, weak basic sites, and reductibility of NiO. The results show that the hydrogenation performance of LaNiO3 perovskite catalysts is enhanced by doping Ca cation in the A site, while the La0.7–Ca0.3–Ni catalyst exhibits the optimum performance and achieves CO2 conversion as high as 83.1% with selectivity of C2–C4 as 11.8%. The characterization results show that the perovskite La0.7–Ca0.3–Ni catalyst has lattice defects in the structure, high proportion of adsorbed oxygen, and more weak basic sites, thus promoting the adsorption and activation of CO2 and then resulting in a higher CO2 conversion.