Nanoporous Pd/TiO2 composites prepared by one-step dealloying and their electrocatalytic performance for methanol/ethanol oxidation

Abstract

A facile one-step dealloying strategy for the preparation of nanoporous Pd/TiO2 composites from the melt-spun Al–Pd–Ti precursor alloys is reported. The structure analysis reveals that the nanoporous Pd/TiO2 composites exhibit a bicontinuous interpenetrating ligament-pore structure. The electrochemical measurements show that the composites observably enhance the electrocatalytic performance towards methanol/ethanol oxidation when the Ti content in the precursor alloys is 0.3–0.7 at%. Among these composites, the nanoporous Pd/TiO2 composites dealloyed from Al84.5Pd15Ti0.5 exhibits the best catalytic activity, which is triple and double times for methanol and ethanol oxidation, respectively, compared with nanoporous Pd. The enhancement is attributed to the synergistic effect between Pd and TiO2. However, when the Ti content is 1 at% in the precursor alloys, the catalytic activity will obviously decline.