Synthesis of selective C₅₊ paraffins directly from CO₂ over Cu-Co catalyst: Dynamic role of Cu to establish the Fischer–Tropsch synthesis process

Cost-effective CO₂ conversion technologies may help achieve negative carbon emissions and mitigate the current climate crisis. Cu-Co bimetallic catalysts have shown great promise in synthesizing liquid fuels directly from CO₂. However, the correlation between CO generated by the reverse water–gas shift (RWGS) reaction and Fischer–Tropsch synthesis over Cu-Co catalysts is not well understood. This study presented that Na-promoted Cu-Co catalysts containing equal amounts of Cu and Co exhibited a high selectivity of C₅₊ hydrocarbons (42.3 %) with 27.1 % CO₂ conversion at 330 °C, 4.0 MPa, and H₂/CO₂ = 1. A competitive RWGS reaction on the Cu sites promoted C–C coupling activity by enhancing the in situ emergent CO followed by CO insertion, which suppresses methanation activity. This study reveals the dynamic role of Cu in Cu-Co-based catalysts for direct conversion of CO₂ to liquid fuels. The results are useful for the rational design of catalysts with practical implications.