A sponge like Pd arrays on Ni foam substrate: Highly active non-platinum electrocatalyst for methanol oxidation in alkaline media

Abstract

In order to commercialize direct methanol fuel cells (DMFCs), the selection of the appropriate catalysts for the replacement of platinum is a basic factor. Herein, we report a sponge like Pd arrays on Ni foam (NF) substrate which is successfully synthesized by a template method. The surface of NF is covered with patterned mesoporous silica (NF-PMS) through electro-assisted self-assembly (EASA) method and Pd nanoparticles are deposited on NF-PMS via the galvanic replacement reaction. After template removal, the synthesized catalyst viz. Pd2/NF-PMS is used for electrocatalytic oxidation of methanol in the alkaline media. The efficiency of template method is proved with the comparison between electrocatalytic activity of Pd2/NF-PMS and Pd2/NF. The synthesized catalyst show more than 5 times higher mass activity and significantly lower onset potential for methanol oxidation as compared with the state-of-the-art Pt/C as well as high antipoisoning property. The excellent results propose Pd2/NF-PMS as an excellent candidate anode for electrocatalytic oxidation of methanol.