Tungsten oxide as active matrix for dispersed carbon-supported RuSe x nanoparticles: Enhancement of the electrocatalytic oxygen reduction

Abstract: Modification of carbon-supported RuSe x nanoparticles with ultra-thin WO3 films results in the enhancement of their electrocatalytic properties towards electroreduction of dioxygen in acid medium (0.5moldm−3 H2SO4) as evidenced from the positive shift of the O2 reduction potential (ca. 150mV) and the higher heterogeneous rate constant (ca. 3 times). An important issue is that the mixed-valent tungsten(VI,V) oxide support is characterized by good electronic and protonic conductivities. Further, not only RuSe x is catalytic but tungsten oxide itself is also capable of promoting the reduction of hydrogen peroxide. This bifunctional activity of the WO3-modified system has been the most pronounced at rather low loadings (e.g. 80μgcm−2) of RuSe x nanoparticles. To facilitate attachment of catalytic particles to glassy carbon substrate, they have been over-coated with Nafion. [Copyright &y& Elsevier]