A core-shell nanoporous Pt-Cu catalyst with tunable composition and high catalytic activity

Composition-controlled fabrication of bimetallic catalysts is of significance in electrochemical energy conversion and storage. A novel nanoporous Pt-Cu bimetallic catalyst with a Pt skin and a Pt-Cu core, fabricated by electrochemically dealloying a bulk Pt-Cu binary alloy using a potential-controlled approach, is reported. The Pt/Cu ratio of the dealloyed nanoporous catalyst can be readily adjusted in a wide composition range by only controlling dealloying potential. The electro-catalytic performance of the nanoporous Pt-Cu catalyst shows evident dependence on Pt/Cu ratio although the surfaces of all the nanoporous catalysts are characterized to be covered by pure Pt. With optimal compositions, the dealloyed nanoporous Pt-Cu catalyst possesses enhanced electrocatalytic activities toward oxygen reduction reaction and formic acid oxidation in comparison with the commercial Pt/C catalyst.