Polycrystalline boron-doped diamond films as supports for methanol oxidation electrocatalysts

The high-area carbon supports that are often used for direct methanol fuel cell electrocatalysts (nanoparticles consisting of platinum, ruthenium and other metals) are being targeted for replacement with diamond in order to take advantage of the superior stability and chemical modifiability of diamond. As a preliminary study, we have examined the electrochemical behavior of boron-doped diamond (BDD) films in 0.5 M H2SO4 using cyclic voltammetry and have also sequentially electrodeposited platinum, and ruthenium by potential cycling in the aqueous solutions of the respective metals between 0.00 and 1.50 V vs. Ag/AgCl. The catalyst composites, i.e., Pt and Pt–Ru, deposited on BDD film substrates, were tested for methanol oxidation. The modified diamond surfaces were also characterized by SEM/EDS, XPS, and AFM.