Mechanochemical Synthesis of Ni–Y/CeO2 Catalyst for Nonthermal Plasma Catalytic CO2 Methanation

Abstract

Nonthermal plasma (NTP)-assisted CO2 methanation can activate and convert stable CO2 molecules under ambient conditions as compared to conventional thermal catalysis (normal operation temperature up to 450 °C), which is a good technique to reduce CO2 emissions and simultaneously utilize the renewable energies like solar and wind. It is critical to develop a robust catalyst with good catalytic performance in order to make NTP catalytic CO2 methanation more competitive. Herein, we present a simple yet efficient synthesis of CeO2-supported Ni catalysts with yttrium (Y) as the promoter (i.e., Ni–Y/CeO2) via mechanochemical synthesis for efficient NTP catalytic CO2 methanation. The developed 7.5Ni–1Y/CeO2 catalyst demonstrated the highest energy efficiency values for CO2 conversion and CH4 yield, i.e., ∼57 gCO2 kWh–1 and ∼17 gCH4 kWh–1, respectively. The CO2-TPD and HRTEM results confirmed that the doped Y positively enhanced the basicity of the catalysts and also decreased the particle size of Ni nanoparticles, thus promoting the NTP catalytic activity of CO2 methanation. The catalyst displayed excellent short-term stability for plasma catalytic CO2 methanation over a 12 h on-stream evaluation, showing a CO2 conversion of 84.2 ± 1.8% and a CH4 selectivity of 83.3 ± 1.9%.