Galvanic Coupling Links Heterogeneous and Molecular Palladium Catalysis in Aerobic Alcohol Oxidation
Year: 2026
Type: preprint
Abstract: Thermochemical catalytic reactions are often composed of coupled electrochemical redox reactions, which may even generate the active catalyst itself. Here we show that oxygen reduction on heterogeneous palladium drives corrosion of Pd(0) through galvanic coupling: electrons released by Pd(0) oxidation are consumed by oxygen reduction on the same catalyst, and the soluble Pd(II) forms a homogeneous complex which catalyzes benzyl alcohol oxidation. Combining corrosion measurements with quantification of Pd(II) and reaction products, we find that supplying more oxygen raises the catalyst potential and accelerates Pd(II) generation and alcohol oxidation. Applying equivalent electrochemical potentials in the absence of oxygen reproduces Pd(II) generation and alcohol oxidation with similar sensitivity to the catalyst potential. Diverting the anodic reaction to a sacrificial anode suppresses Pd(II) supply and thus the thermochemical reaction rate. Hence, the primary role of oxygen is to set the potential for generating the active catalyst, while palladium corrosion is the kinetic link to thermochemical turnover. Together, our results show that galvanic coupling provides a framework that links electrochemistry and thermochemical catalysis.
Source: ChemRxiv
Institution: The University of Texas at Austin
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7222223346