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 CO2/CH4 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 CH3COOH generation, while oxygen vacancies (Ov) contributed to the formation of CH3OH. The gaseous and interfacial simulations verified the strong chemisorption of CO2 and key O-containing radicals (O, OH, COOH) on Ov, thereby shifting the reaction from high-barrier surface to the gas phase via the barrierless Eley-Rideal mechanism. The specifically Ov-assisted pathways for R-COOH/R-OH generation over the custom-designed Co-MgAlO-Ov 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.