Electrocatalysis at Organic–Metal Interfaces: Identification of Structure–Reactivity Relationships for CO₂ Reduction at Modified Cu Surfaces

The limited selectivity of existing CO₂ reduction catalysts and rising levels of CO₂ in the atmosphere necessitate the identification of specific structure-reactivity relationships to inform catalyst development. Herein, we develop a predictive framework to tune the selectivity of CO₂ reduction on Cu by examining a series of polymeric and molecular modifiers. We find that protic species enhance selectivity for H₂, hydrophilic species enhance formic acid formation, and cationic hydrophobic species enhance CO selectivity. ReaxFF reactive molecular dynamics simulations indicate that the hydrophilic/hydrophobic modifiers influence the formation of surface hydrides, which yield formic acid or H₂. These observations offer insights into how these modifiers influence catalytic behavior at the non-precious Cu surface and may aid in the future implementation of organic structures in CO₂ reduction devices.