In-Situ Infrared Spectroscopic Investigation of Pyridine-Mediated CO2 Reduction on Pt Electrocatalysts

The pyridine-mediated electrochemical reduction of CO₂ ­to methanol, formate, and formaldehyde was first demonstrated by Bocarsly et. al in 1994. Since then, many mechanistic investigations of this process have been conducted using reactivity, cyclic voltammetry, or computational methods; however, direct experimental mechanistic investigation has been lacking. We employ surface-enhanced infrared absorption spectroscopy, coupled with traditional electrochemical techniques in order to probe the electrochemical interface during the pyridine-mediated electrochemical reduction of CO₂ on Pt electrocatalysts. Previously proposed mechanisms are discussed and refined in light of new insights obtained in these studies.