Energy-efficient CO(2) conversion to multicarbon products at high rates on CuGa bimetallic catalyst
Lei Chen, Junmei Chen, Wei‐Wei Fu, Jiayi Chen, Di Wang, Yukun Xiao, Shibo Xi, Yongfei Ji, Lei Wang
Abstract
Electrocatalytic CO2 reduction to multi-carbon products is a promising approach for achieving carbon-neutral economies. However, the energy efficiency of these processes remains low, particularly at high current densities. Herein, we demonstrate that the low energy efficiencies are, in part, sometimes significantly, attributed to the high concentration overpotential resulting from the instability (i.e., flooding) of catalyst-layer during electrolysis. To tackle this challenge, we develop copper/gallium bimetallic catalysts with reduced activation energies for the formation of multi-carbon products. Consequently, the reduced activation overpotential allows us to achieve practical-relevant current densities for CO2 reduction at low cathodic potentials, ensuring good stability of the catalyst-layer and thereby minimizing the undesired concentration overpotential. The optimized bimetallic catalyst achieves over 50% cathodic energy efficiency for multi-carbon production at a high current density of over $$1.0 \, {{\rm{A}}} \, {{\rm{cm}}}^{-2}$$ . Furthermore, we achieve current densities exceeding $$2.0 \, {{\rm{A}}} \, {{\rm{cm}}}^{-2}$$ in a zero-gap membrane-electrode-assembly reactor, with a full-cell energy efficiency surpassing 30%. Electroreduction of CO2 to fuels and chemicals is promising but hindered by its low energy efficiency. Here, the authors develop Cu/Ga bimetallic catalysts with reduced activation energies to mitigate the high concentration overpotential, thereby achieving high energy efficiency for CO2 reduction.