A Systematicin SituInfrared Study of the Electrooxidation of C3 Alcohols on Carbon-Supported Pt and Pt–Bi Catalysts

Abstract

The electrooxidation of C3 alcohols (1-propanol, 2-propanol, 1,2-propanediol, 1,3-propanediol, and glycerol) has been studied in alkaline medium on Pt/C and Pt9Bi1/C catalysts by cyclic voltammetry and in situ FTIR spectroscopy. Both catalysts were synthesized with metal particle sizes below 5 nm and were characterized by TGA, AAS, and XRD. The modification of Pt by 10 at. % of Bi decreases the oxidation onset potentials of C3 alcohols down to ca. 200 mV. In situ FTIR spectroscopy measurements indicated clearly that the presence of Bi also led to avoid the C–C bond cleavage during alcohol electrooxidation reactions and, hence, to favor the formation of value-added C3 compounds. Moreover, with respect to a Pd-based catalyst, Pt9Bi1/C presented much higher electrocatalytic activity at low potentials. Systematic evaluation of the positions and intensity changes of absorption bands as a function of the electrode potential allowed determining reaction pathways of electrooxidation of C3 alcohols. It has been sh...