Chemical Modifications of Ag Catalyst Surfaces with Imidazolium Ionomers Modulate H2 Evolution Rates during Electrochemical CO2 Reduction

• DOI: 10.1021/jacs.1c06212
• Publication Date: 2021-09-02T10:10:07Z
• Authors: David M. Koshy; Sneha A. Akhade; Adam Shugar; Kabir Abiose; Jingwei Shi; Siwei Liang; James S. Oakdale; Stephen E. Weitzner; Joel B. Varley; Eric B. Duoss; Sarah E. Baker; Christopher Hahn; Zhenan Bao; Thomas F. Jaramillo
• Keywords: Chemical reduction

Bridging polymer design with catalyst surface science is a promising direction for tuning and optimizing electrochemical reactors that could impact long-term goals in energy sustainability. Particularly, the interaction between inorganic surfaces organic-based ionomers provides an avenue to both steer reaction selectivity promote activity. Here, we studied role of imidazolium-based electrocatalytic CO2 reduction CO (CO2R) on Ag found they produce no effect CO2R activity yet strongly competing hydrogen evolution (HER). By examining dependence HER rates concentrations HCO3–, developed kinetic model attributes promotion intrinsic HCO3– by imidazolium ionomers. We also show varying ionomer structure changing substituents ring modulates promotion. This ionomer-structure was analyzed via Taft steric parameters density functional theory calculations, which suggest bulk from functionalities reduces access surface, thus limiting promotional effect. Our results help develop rules ionomer–catalyst interactions motivate further work into precisely uncovering interplay primary secondary coordination determining behavior.