Monolayer-Level Ru- and NbO[sub 2]-Supported Platinum Electrocatalysts for Methanol Oxidation

Abstract

We developed electrocatalysts with a monolayer-level Pt content for methanol oxidation by depositing Pt or (, Ir, Rh, Pd) on the surfaces of Ru nanoparticles through the galvanic replacement of Cu adlayers and by chemically reducing Pt ions on a oxide surface. Compared with a commercial alloy catalyst, the electrocatalyst with a monolayer of showed three times higher Pt mass activity and improved durability for methanol oxidation. The activity originates from the efficient bifunctional mechanism as well as the electronic effect that weakens the bonding facilitated by optimized size of Pt-free and Pt-covered Ru support. Electrocatalysts comprising mixed-metal on Ru nanoparticles also had higher activity than the commercial one but did not surpass the electrocatalyst. The properties of the electrocatalysts composed of a monolayer amount of Pt deposited on niobium oxide nanoparticles indicate that holds considerable promise as a support for a Pt monolayer for methanol oxidation.