Silver-Doped Porous Copper Catalysts for Efficient Resource Utilization of CO-Containing Flue Gases.

CO is both a key intermediate in the electrocatalytic conversion of CO₂ and a valuable C₁ resource, with the potential to reduce carbon emissions and mitigate the energy crisis. However, industrially emitted CO remains underutilized due to inefficiencies and economic challenges. Electrocatalytic CO reduction offers a promising approach for the efficient and environmentally friendly utilization of CO-containing flue gases. Nevertheless, current technologies face limitations, such as low operating currents and difficulties in adaptation to complex reaction gas components. Here, we report a low-cost silver-doped porous copper oxide (Ag-pCuO) catalyst. The doping of a moderate amount of Ag (0.875% doping) endows porous CuO with highly selective Cu-Ag active sites, enhanced CO adsorption, and improved surface valence stability, allowing Ag_0.875%-pCuO to achieve remarkable catalytic performance in a carbon-doped titanium-based membrane electrode assembly electrolytic cell. It achieves a remarkable C₂₊ faradic efficiency of up to 94% at a high current density of -4 A under a simulated calcium carbide furnace gas atmosphere and demonstrates exceptional stability, with only a 6.08% decline in C₂₊ faradic efficiency after over 110 h of continuous operation. In summary, this research presents a novel approach for applying Ag-doped copper-based catalysts to industrially utilize CO-containing flue gases, especially from calcium carbide furnaces.