Mesoporous noble metals are an emerging class of cutting-edge nanostructured catalysts
due to their abundant exposed active sites and highly accessible surfaces. Although various
noble metal (e.g. Pt, Pd and Au) structures have been synthesized by hard- and soft--
templating methods, mesoporous rhodium (Rh) nanoparticles have never been generated via
chemical reduction, in part due to the relatively high surface energy of rhodium (Rh) metal.
Here we describe a simple, scalable route to generate mesoporous Rh by chemical reduction
on polymeric micelle templates [poly(ethylene oxide)-b-poly(methyl methacrylate)
(PEO-b-PMMA)]. The mesoporous Rh nanoparticles exhibited a B2.6 times enhancement
for the electrocatalytic oxidation of methanol compared to commercially available Rh catalyst.
Surprisingly, the high surface area mesoporous structure of the Rh catalyst was thermally
stable up to 400 C. The combination of high surface area and thermal stability also enables
superior catalytic activity for the remediation of nitric oxide (NO) in lean-burn exhaust
containing high concentrations of O2.