Revisiting glycerol electrooxidation by applying derivative voltammetry: From well-ordered bulk Pt to bimetallic nanoparticles

Metal nanoparticles are used to catalyze glycerol electrooxidation reaction aiming energy and chemical conversion, yielding carbonyl compounds with high market prices. The energy required to start glycerol electrooxidation is directly measured by the onset potential, determined by stationary voltammetry (dE/dt) in the form of a graph dj/dE (voltammogram). This topic has received much attention in recent years; however, a systematic rationalization of themethods to investigate the newnanomaterials is lacking to date. Here we target the identification of onset potential by revising glycerol electrooxidation on bulk well-ordered surfaces, Pt/C nanoparticles (NPs), and bimetallic NPs by applying derivative voltammetry (d(2)E/dt(2)). We revisit data regarding bulk Pt(111), Pt(110), Pt(100), and polycrystalline surface; FTIR in situ of isotopically labeled glycerol on bulk Pt and Pt/C; and concerning Sb-decorated Pt/C NPs. Our analysis shows that the use of conventional voltammetry may hide steps of the reaction and misguide the identification of the onset potential, which is accurately obtained by derivative voltammetry. The distortion induced on the function dj/dE created by an inappropriate current normalization method may disturb the threshold of the function, and the onset potential accordingly. This last point is critical since the catalystmay be mistakenly accepted as an active one. (C) 2020 Elsevier B.V. All rights reserved.