Disentangling metallic cobalt sites and oxygen vacancy effects in synergistic plasma-catalytic CO2/CH4 conversion into oxygenates
Liguang Dou, Yadi Liu, Yuan Gao, Jiangwei Li, Xiucui Hu, Shuai Zhang, Kostya Ostrikov, Tao Shao
Abstract
Plasma-catalysis is a highly promising renewable-energy-based solution for decarbonization of industrial and environmental catalysis. However, urgent insights how to develop plasma-specific catalysts and synergize with the unique plasma effects are vitally needed for CO 2 /CH 4 utilization. Herein we provide guiding principles for catalysts design enabling discriminative production of liquid oxygenates. Comprehensive tests revealed that metallic Co was critical to enhance the CH 3 COOH generation, while oxygen vacancies (O v ) contributed to the formation of CH 3 OH. The gaseous and interfacial simulations verified the strong chemisorption of CO 2 and key O-containing radicals (O, OH, COOH) on O v , thereby shifting the reaction from high-barrier surface to the gas phase via the barrierless Eley-Rideal mechanism. The specifically O v -assisted pathways for R-COOH/R-OH generation over the custom-designed Co-MgAlO-O v multiphase structures are proposed. This study confirms that the microstructure design can modulate the radical adsorption and kinetic factors of the plasma-induced interfacial catalysis leading towards the plasma-electrified energy conversion.