Dependence of onset potential for methanol electrocatalytic oxidation on steric location of active center in multicomponent electrocatalysts

The dependence of onset potential for methanol oxidation on steric location of the active center in multicomponent electrocatalysts is reported in this paper. In general, the onset potential decreases with the decrease of lattice parameter in the catalysts investigated. By comparison of cyclic voltammetry (CV) and X-ray diffraction (XRD) results, it has been found that the onset potential decreases with decreasing lattice parameter for Bi and Pb series catalysts. The dependence of onset potential and lattice parameter showed a different tendency for Ir and Rh series catalysts, that is, an initial increase and then a decrease. This dependence may be due to the different steric locations of the active center corresponding to the lattice parameters (a). In addition, the current densities of methanol oxidation were also compared. Ir series catalysts displayed higher peak current densities than PtRu/C catalyst. Correlation of the structures and electrocatalytic activity of multicomponent catalysts were discussed.