Direct methanol oxidation at low overpotentials using Pt nanoparticles electrodeposited at ultrathin conductive RuO2 nanoskins

Small (primarily 2–4 nm) Pt nanoparticles electrodeposited at Ti-supported RuO2 nanoskins, designated as Pt/RuO2(Ti), are highly active for electrocatalytic oxidation of methanol (CH3OH) in acid electrolyte, with peak potentials among the lowest reported anywhere for RuO2-supported Pt. The Pt-modified RuO2 nanoskin is equally effective for CH3OH oxidation whether one or both sides of the Ti-foil substrate is coated or whether the RuO2 nanoskin is electrolessly deposited at the Ti substrate as a single layer or in multiple layers. Current densities for methanol oxidation are ∼2× lower than previously reported, owing to a bimodal distribution of both highly active (2–4 nm) and less active larger (> 5 nm) Pt particles. The methods reported here comprise a means of expressing highly active, nanostructured, bifunctional electrocatalytic coatings on substrates of essentially any geometry and minimizing the quantity of RuO2 necessary.