Tuning the Selectivity of Liquid Products during CO Electroreduction

Abstract

The electrochemical carbon dioxide reduction (eCO2RR) into value-added chemicals and fuels offers a sustainable route to close the anthropogenic carbon cycle and store the renewable sources' excess energy into chemical bonds. Typically, eCO2RR/eCORR studies employ reactant reduction in the cathode and oxygen evolution reaction in the anode. The membrane (membrane electrode assembly configuration) facilitates the ion transport between the two electrodes and chemically isolate the occurring electrochemical half-reactions. It should be noted that investigators have conceptualized the use of ion-exchange membranes in order to improve the reaction energy efficiency and rate. However, the impact of membrane properties on reaction selectivity, stability, and efficiency remains unexplored.Herein, we investigated the role of anion exchange membrane on the CO reduction performance using a membrane electrode assembly configuration. This talk will provide insights into the ion-exchange membrane's role in the electrocatalytic reduction of CO. We will show how the membrane properties determine the product crossover, product selectivity, and stability. For example, we will discuss: i) the impact of membrane thickness on the product crossover and applied potential, ii) the role of the membrane on the cell stability, iii) the possibility of various membrane functional groups to tune the reaction selectivity and stability, and iv) the role of counter-ion, ion exchange capacity (IEC), and membrane reinforcement on the cell performance. This work will provide a first step toward designing an ion-exchange membrane with the desired characteristics for CO electroreduction.