Acidic Media Impedes Tandem Catalysis Reaction Pathways in Electrochemical CO2 Reduction

Electrochemical CO2 reduction (CO2R) in acidic media with Cu-based catalysts tends to suffer from lowered selectivity towards multicarbon products. This could principle be mitigated using tandem catalysis, whereby the *CO coverage on Cu is increased by introducing a CO generating catalyst (e.g. Ag) close proximity. Although this has seen significant success neutral/alkaline media, here we report that such strategy becomes impeded electrolyte. was investigated through co-reduction of 13CO2/12CO mixtures series and CuAg catalysts. These experiments provide strong evidence for occurrence catalysis neutral its curtailment under conditions. Density functional theory simulations suggest presence H3O+ weakens binding energy Cu, preventing effective utilization tandem-supplied CO. Our findings also other unanticipated insights into reaction pathway important design considerations CO2R media.