Fabrication of a mesoporous Pt-carbon catalyst by the direct templating of mesoporous Pt-alumina for the methanol electro-oxidation

Abstract

Mesoporous Pt-carbon catalysts were directly fabricated using mesoporous Pt-alumina as a template with a metal source and using poly(divinylbenzene) as a carbon precursor. Two types of mesoporous Pt-alumina templates were prepared by employing different calcination conditions (PtAl-A and PtAl-N were produced by the calcination in a stream of air and nitrogen, respectively). Both the mesoporous Pt-aluminas served as efficient templates for the fabrication of replicated Pt-carbon catalysts (PtC-A and PtC-N). The PtC catalysts showed high surface area with a narrow pore size distribution centered at ca. 4.0 nm. Together with pore-confined metal growth, the characteristic feature of the template, such as a strong interaction of metal species with the support was beneficial for the formation of highly dispersed Pt particles on the replicated mesoporous carbon catalysts. The mesoporous Pt-carbon (PtC) catalysts exhibited a higher metal dispersion than Pt catalyst impregnated on CMK-3 (Pt/CMK-3). Futhermore, the PtC-N catalyst exhibited a higher metal dispersion than the PtC-A catalyst. Methanol electro-oxidation experiments revealed the catalytic performance was closely related to the metal dispersion in the supported catalysts. The PtC-N catalyst with the highest metal dispersion exhibited the best catalytic performance in methanol electro-oxidation.