Atomically dispersed Pt catalyst on ceria-carbon to suppress C-C cleavage in glycerol electrooxidation

Abstract

Glycerol, a low-cost and abundant byproduct of biodiesel production, has attracted attention as a feedstock for conversion into value-added chemicals. To maximize the economic value of products, maintaining three carbons (C3) as the dominant product is important yet difficult to achieve at high potentials due to the favorable C-C bond scission. We demonstrate that atomically dispersed Pt catalyst anchored on defective ceria-carbon selectively controls the glycerol electrooxidation reaction (GEOR), favoring C3 products. The isolated Pt sites favored single-carbon adsorption, preventing multi-carbon binding and subsequent cleavage up until high potential of 1.2 VRHE. The catalyst maintained nearly 70 % of C3 selectivity across various potentials with high glycerate productivity and selectivity. In contrast, catalysts with Pt nanoparticles rapidly shifted towards C2 and C1 products, especially glycolate and formate as potential increases. Moreover, Pt single atoms on the catalyst maintained high glycerate product yield without much Pt agglomeration under 48 hr operation. Beyond batch operation, the Pt single atom catalyst was validated in a continuous flow-cell reactor. Glycerate remained as the major product, reaching the selectivity of 50 % as potential increases and exhibited the yield of 21.7 mmol L -1 mgPt -1 h -1 at 1.2 VRHE.This work highlights atomic dispersion on defect-engineered supports as a powerful strategy to control electrocatalytic pathways in GEOR via suppressing C-C cleavage.