Wrapping a monoparticulate layer of 2–3-nm RuO 2 around the fibers comprising porous SiO 2 filter paper produces a conductive nanoshell in which ∼90% of the RuO 2 units are surface-sited, creating the equivalent of a supported single-unit layer of the oxide. The room temperature electronic conductivity, normalized for the dimensions of the total RuO 2 (SiO 2 ) object, increases with calcination temperature reaching a maximum of 830mScm −1 for a 200°C-calcined paper, and then sharply decreases at higher temperatures as the nanoparticles in the ultrathin RuO 2 shell ripen and disrupt the connectivity. The calcination temperature also influences the electrochemical capacitance, which is optimized at 150°C with a RuO 2 -normalized specific capacitance of 850Fg −1 . Calcining the RuO 2 (SiO 2 ) papers to temperatures ⩾250°C reduces the electrochemical capacitance due to structural ordering and ripening of the RuO 2 nanoparticles composing the coating. The electrochemical capacitance and the magnitude of the electronic conductivity of the RuO 2 (SiO 2 ) paper are unaffected by exposure to air, humidified air, Ar, humidified Ar, or methanol-saturated Ar at 25°C. Exposing the papers at room temperature to either pure H 2 or humidified H 2 significantly reduces the pseudocapacitance and electronic conductivity. X-ray photoelectron spectroscopy confirms reduction of the RuO 2 to Ru and scanning electron microscopy demonstrates shrinkage-induced stress cracking and disruption of the H 2 -reacted nanoscale coating. These results indicate that the RuO 2 (SiO 2 ) architecture can serve as a rugged, inexpensive, and conductive gas-diffusion scaffold for the design of a carbon- and ionomer-free anode for direct methanol fuel cells.