(Invited) Selective and Efficient Electrochemical CO2 Reduction Reaction from Cu and Cu-M Binary Alloys

Abstract

Electrochemical CO2 reduction reaction (CO2RR) has attracted a great deal of attention due to its potential to convert CO2 into valuable chemical fuels and feedstocks. The production of C2+ chemicals, such as ethylene and ethanol, from CO2RR is particularly important because of their large market demand. However, several challenges must be addressed before CO2RR can be commercially scaled up, including high overpotential, low selectivity, and poor CO2 solubility in aqueous solutions. In this presentation, I will discuss our recent efforts to overcome these challenges in CO2RR by using a gas diffusion electrode (GDE) to achieve a CO2RR current density of over 100 mA/cm2 in a flow reactor. First, I will highlight the crucial role of the local CO2RR environment in promoting C-C coupling on Cu surfaces, and I will present strategies for controlling this environment based on steady-state modeling and monodisperse Cu2O nanoparticles as a model catalyst system. Using this approach, we have been able to produce C2+ products, such as ethylene and ethanol, with a Faraday efficiency of over 70% at a current density of over 300 mA/cm2 in near-neutral electrolytes. Additionally, I will discuss the impact of alloying Cu with Ni and Zn on tailoring product selectivity. By introducing elements with different CO binding strengths, we can significantly alter the selectivity for hydrocarbons and alcohols. I will provide further details on these findings during the presentation.