Mechanochemical Synthesis of Bimetallic NiCo Supported on a CeO₂ Catalyst with Less Metal Loading for Non-Thermal Plasma Catalytic CO₂ Hydrogenation

Non-thermal plasma (NTP) catalysis is a promising technology for CO2 valorization with renewable H2, in which catalyst design one of the key aspects to progress hybrid technology. Herein, bimetallic NiCo supported on CeO2 catalysts, that is, NiCo/CeO2, were developed less metal loading ∼2 wt % using mechanochemical synthesis NTP-catalytic methanation. During synthesis, different addition orders Ni and Co precursors investigated, results show NiCo1/CeO2-I (which was prepared by simultaneous precursors, protocol I) exhibited highest conversion (∼60%) CH4 selectivity/yield (∼80%/∼50%), whereas NiCo1/CeO2-II NiCo1/CeO2-III catalysts (prepared sequential protocols II III) showed very poor catalytic performance. Characterization suggested I, prefer alloy, concentrated oxygen vacancies surface high basicity are retained as well. Such properties responsible activation hydrogenation under NTP conditions, explained proposed mechanisms.