Synthesis by Spray Pyrolysis of Mesoporous NbRu_yO_z as Electrocatalyst Supports in Fuel Cells

In this study, spray pyrolysis was used to produce two mesoporous powders, niobium oxide and niobium oxide with 12% ruthenium (by weight, metal basis, based on precursor mixture), as potential catalytic supports in fuel cells. Niobium oxide and ruthenium-modified niobium oxide powders displayed spherical particle morphology with internal mesoporosity introduced by surfactant templating, providing surface areas as high as 183 and 167 m 2 /g, respectively, after postprocessing that included an acid etch and calcination. The incorporation of ruthenium into niobium oxide, coupled with appropriate postsynthesis treatment, resulted in a material with electrical resistance that was reduced by roughly 5 orders of magnitude relative to unmodified niobium oxide. The structure and properties of these two materials subject to different postprocessing treatments were extensively characterized, and dynamic factors related to aerosol and subsequent thermal processing of these materials are discussed. Cyclic voltammetry showed that the ruthenium-modified material possessed activity for methanol oxidation in a basic environment.