title: Mesoporous nanostructured Nb-doped titanium dioxide microsphere catalyst supports for PEM fuel cell electrodes.
abstract: Crystalline microspheres of Nb-doped TiO(2) with a high specific surface area were synthesized using a templating method exploiting ionic interactions between nascent inorganic components and an ionomer template. The microspheres exhibit a porosity gradient, with a meso-macroporous kernel, and a mesoporous shell. The material has been investigated as cathode electrocatalyst support for polymer electrolyte membrane (PEM) fuel cells. A uniform dispersion of Pt particles on the Nb-doped TiO(2) support was obtained using a microwave method, and the electrochemical properties assessed by cyclic voltammetry. Nb-TiO(2) supported Pt demonstrated very high stability, as after 1000 voltammetric cycles, 85% of the electroactive Pt area remained compared to 47% in the case of commercial Pt on carbon. For the oxygen reduction reaction (ORR), which takes place at the cathode, the highest stability was again obtained with the Nb-doped titania-based material even though the mass activity calculated at 0.9 V vs RHE was slightly lower. The microspherical structured and mesoporous Nb-doped TiO(2) is an alternative support to carbon for PEM fuel cells.
authors.affiliation: Institut Charles Gerhardt, Agrégats, Interfaces et Matériaux pour l'Energie, UMR CNRS 5253, Université Montpellier II, 34095 Montpellier Cedex 5, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Chevallier
authors.forename: Alexander
authors.initials: A
authors.lastname: Bauer
authors.forename: Sara
authors.initials: S
authors.lastname: Cavaliere
authors.forename: Rob
authors.initials: R
authors.lastname: Hui
authors.forename: Jacques
authors.initials: J
authors.lastname: Rozière
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Jones