Copper-Tin Alloys for the Electrocatalytic Reduction of CO2 in an Imidazolium-Based Non-Aqueous Electrolyte

The ability to synthesize value-added chemicals directly from CO2 will be an important technological advancement for future generations. Using solar energy to drive thermodynamically uphill electrochemical reactions allows for near carbon-neutral processes that can convert CO2 into energy-rich carbon-based fuels. Here, we report on the use of inexpensive CuSn alloys to convert CO2 into CO in an acetonitrile/imidazolium-based electrolyte. Synergistic interactions between the CuSn catalyst and the imidazolium cation enables the electrocatalytic conversion of CO2 into CO at −1.65 V versus the standard calomel electrode (SCE). This catalyst system is characterized by overpotentials for CO2 reduction that are similar to more expensive Au- and Ag-based catalysts, and also shows that the efficacy of the CO2 reduction reaction can be tuned by varying the CuSn ratio.