Surfactant-Free Synthesis of Pd(CeOx)/C Catalyst for Electrochemical Glycerol Oxidation in Alkaline Medium: Glycerate and Energy Co-Production

Using a Pd(CeOx)/C catalyst prepared via a clean, water-based bromide anion exchange method, we successfully converted glycerol into glycerate. Compared to standard Pd/C, this catalyst, featuring palladium nanoparticles supported on carbon and modified with cerium oxide (CeOx), significantly enhances catalytic activity. The Pd(CeOx)/C catalyst achieved a 93% higher current density, and when used as an anode in a direct glycerol fuel cell, it delivered a 76% increase in power density and co-produced valuable glycerate. Transmission electron microscopy (TEM) revealed a uniform distribution of particles and a strong interaction between palladium and the cerium oxide, which enhanced the catalytic performance. Spectroelectrochemistry and high-performance liquid chromatography (HPLC) analyses confirmed the selective conversion of glycerol to glycerate regardless of voltage or CeOx modification. This selectivity is attributed to the elevated Pd d-band, which prevents C-C bond cleavage and favors C3 product formation. Interestingly, CeOx acted as a co-catalyst, improving Pd activity even though the Pd(CeOx)/C catalyst contains 40% less noble metal than the Pd/C catalyst.