TiO2 nanotube supported PdNi catalyst for methanol electro-oxidation

A novel PdNi/TiO2 nanotube electrocatalyst was successfully prepared by the surface reductive deposition method using the PdCl2 and NiSO4 as precursors and porous TiO2 nanotube as carrier. The structural and electrochemical properties of the PdNi/TiO2 nanotube catalyst were characterized by XRD, TEM and electrochemical analysis. The experiments results showed that TiO2 nanotube had large surface area and porous structure that is preferable to the dispersion of nanosized PdNi on the surface of the TiO2 nanotube support. The cyclic voltammograms in 1 mol L-1 CH3OH and 1 mol L-1 H2SO4 showed that the large oxidation peak potential was about 0.94 V on the positive irreversible scan and another acute peak of methanol oxidation was 0.85 V on the reverse scan that was much bigger than that of the standard PtRu/C catalyst, the PdNi/TiO2 nanotube electrocatalyst had higher catalytic activity for methanol electro-oxidation than standard PtRu/C catalyst. The methanol oxidation mechanism of the PdNi/TiO2 nanotube catalyst was mainly depended on the photocatalytic mechanism of TiO2 and the synergistic effect between PdNi bimetal and the carrier TiO2 nanotube. The PdNi/TiO2 nanotube catalyst should be a promising candidate for direct methanol fuel cell. (C) 2012 Elsevier B.V. All rights reserved.