Ce⁴⁺-Doped CuO Mesoporous Nanosheets for CO₂ Electroreduction to C₂H₆ with High Selectivity under a Wide Potential Window in a Flow Cell

Abstract

CO 2 electrocatalytic reduction (CO 2 ER) to multiple carbonous products is a valuably sustainable way to obtain fuels and chemicals. However, its practical application is still hindered by low selectivity and activity under large current density. A flow cell enables CO 2 ER to operate at high current densities by mitigating the CO 2 mass transport limitation issue. Here, we report Ce 4+ -doped CuO mesoporous nanosheets affording high selectivity and activity toward CO 2 ER to C 2 H 6 in a flow cell. Ce 4+ doping induces oxygen vacancies and modulates the electron distribution of CuO, which enhances the adsorption intensity and coverage of a *CO intermediate for further C−C coupling to finally produce C 2 H 6 . Moreover, Ce 4+ doping can well protect Cu 2+ species from being reduced during CO 2 ER, which guarantees high selectivity and stability for C 2 H 6 generation. As a result, the optimal Ce 0.03 Cu 0.97 O 0.83 exhibits large partial current densities of 55.3 ± 1.6−235.5 ± 4.3 mA cm −2 with Faradaic efficiencies over 50% for ethane under a wide potential window of −0.5 to −0.9 V in a flow cell. This work clarifies that the CuO nanostructure doped with lanthanide metal ions can modulate the reaction pathway of CO 2 ER to C 2 H 6 in a flow cell.

Mo4+-Doped CuS Nanosheet-Assembled Hollow Spheres for CO2 Electroreduction to Ethanol in a Flow Cell

“…Among various strategies, heteroatom doping is a simple and effective strategy to adjust the chemical valence state and the electron structure of the active sites on the catalyst surface via hybridizing energy levels with the original catalyst. CuO doped by high valence Ce 4+ ions can improve *CO adsorption and C–C coupling for CO 2 RR to ethane by redistributing electrons of CuO . Tetravalent molybdenum chalcogenide of MoSeS can stabilize the *CO*OH intermediate on adjacent Mo sites to produce CO during CO 2 RR .…”