Efficient Reduction of CO₂ to CO Using Cobalt-Cobalt Oxide Core-Shell Catalysts

The route of converting CO₂ to CO by reverse water-gas shift (RWGS) reaction is of particular interest due to the direct use of CO as feedstock in many significant industrial processes. Here, an engineered cobalt-cobalt oxide core-shell catalyst (Co@CoO) with nanochains structure has been made for the efficient reduction of CO₂ to useful CO. Owing to the excellent performance for H₂ activation of metal nanoparticles and the enhanced absorption and activation for CO₂ molecule of defective metal oxides, the unique synergistic effect of metallic Co and encapsulating coordinatively unsaturated CoO species shows high performance for clean generation of CO under moderate and practical conditions. Furthermore, with N-dopant into the defective CoO shell, the Co@CoO-N achieves the highest conversion of 19.2 % and an exceptional CO evolution rate of 96 mL min^-1  g_cat^-1 at 523 K with a gas hourly space velocity (GHSV) of 42,000 mL g_cat^-1  h^-1 , which is comparable with the previously reported materials under identical conditions.