Speaker
Description
Fundamentals behind halide-induced promotion effects in catalysis remain debated and lacking reliable structure-property relationships for reactions including the electrochemical CO$_{2}$ reduction (CO$_{2}$RR) hinder rational catalyst and electrolyte design. Here we employ in situ atomic force microscopy, cyclic voltammetry, and DFT theory to unveil the potential-dependent complex surface phase behavior of copper catalysts exposed to halide-containing electrolytes. We show that iodide adsorbs competitively with hydroxide, leading to unexpected changes in halogen surface coverages. We correlate global electrochemical fingerprints of specific iodide adsorption with local in situ structure information. In particular, we prove that compact halogen layers are absent over extended CO$_{2}$RR potentials and show that selectivity toward multi-carbon species is altered by the potential program applied in situ prior to catalysis. This work scrutinizes current assumptions made to interprete halogen promotion effects in CO$_{2}$RR, provide a basis on which theoretical modeling of electrochemical data can be advanced, and inspires innovative catalyst design strategies.
| Abstract Number (department-wise) | ISC 08 |
|---|---|
| Department | ISC (Roldán) |
