Mesoporous Pt and Pt/Ru alloy electrocatalysts for methanol oxidation

Mesoporous Pt and Pt/Ru catalysts with 2D-hexagonal mesostructure were synthesized using a triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) copolymer (Pluronic F127®) template, on a gold support. Large electrochemical surface areas were observed for the catalysts prepared at high overpotentials. Compared to the Pt catalyst, the Pt/Ru alloy containing 3 at% of Ru exhibited lower onset potential and more than three times the limit mass activity for methanol oxidation. This behavior is assigned to the larger pore size of the mesoporous Pt and Pt/Ru catalysts obtained with this template that seems to improve the methanol accessibility to the active sites compared to those obtained using lyotropic liquid crystals.

Research highlights▶ Mesoporous Pt and Pt/Ru catalysts with 2D-hexagonal mesostructure were synthesized using a Pluronic F127® template. ▶ Large electrochemical surface areas were observed for the catalysts prepared at high overpotentials. ▶ The Pt/Ru alloy (3 at% Ru) exhibited more than three times the limit mass activity for methanol oxidation than Pt. ▶ The larger pore size of the mesoporous Pt and Pt/Ru catalysts improve the methanol accessibility to the active sites.