Activity and Durability of PtRuP Catalysts and Their Atomic Structures

Abstract

Carbon supported PtRuP catalyst 2 nm in size was synthesized by electroless plating method by using HPH2O2 as a reducing agent as well as a source of P. Chelate ligand of citric acid was added in synthetic solution to decease difference of reduction potentials between Pt and Ru ions. Electrochemical measurements showed that the addition of chelate ligand decreased the difference from 0.42 V to 0.31 V and that CO tolerance, methanol oxidation activity and durability were improved in PtRuP catalyst synthesized with the chelate ligand. XRD and EXAFS analyses revealed that mixing state of Pt and Ru atoms was promoted in the PtRuP catalyst. The improved CO tolerance, methanol oxidation activity and durability arise from the well-mixed Pt and Ru atoms in the PtRuP catalyst, which supported bi-functional mechanism.