Preparation Of Pt/Cu Electrocatalysts By Using Cu₂O As Template Materials

The issue of energy is the major problem in the human society, which is related to the civilization in today’s society, so people committed to the development of new energy and improving the efficiency of energy.Platinum is a precious transition metal with excellent catalytic and electrical properties, as well as enhanced resistance to corrosion, and it has been widely employed in chemical, petrochemical, pharmaceutical, electronic and automotive industries. Pt can serve as a catalyst in the reduction of pollutant gases emitted from automobiles, as well as in the synthesis of nitric acid, oil cracking, and proton-exchange membrane（PEM） fuel cells. A fuel cell is an electrochemical device that oxidizes a fuel at the anode and reduces oxygen from air at the cathode to produce electricity. Unsupported platinum was the first practical working electrocatalyst in low-temperature fuel cells. Pt black electrodes were initially developed in the early 1960 s and later became the primary electrocatalyst of choice for the electrode. Pt black is metallic platinum with an average agglomerate size of approximately 1 nm and an electrochemical surface area of about 15 m2·g-1. Pt-containing catalysts are anchored on both the anode and the cathode in fuel cells to catalyze the fuel oxidation and the oxygen reduction reactions.In this paper, a simple template method was used to prepare Pt/Cu bimetallic electrocatalyst. By using Cu₂O as a template material, D-glucose as a reducing agent and H2 Pt Cl6 as Pt precursor, first to prepare Pt/Cu₂O hollow structure under the effect of glucose and chloroplatinic acid, and then Pt/Cu₂O was etched by HCl to form a hollow structure Pt /Cu bimetallic alloy.Furthermore, the formation mechanism of Pt /Cu bimetallic alloy was studied. The influences of H2 Pt Cl6 and glucose on the morphology of alloy were also investigated. It was found that Pt nanocrystals were produced through the Glavance reaction of Pt Cl62-, H+ and Cu₂O. At first Cu₂O was transferred to a hollow structure by etching and reduction effect of H+. Then glucose entered into Cu₂O hollow structure, and Cu was internally generated. At the same time glucose acted as a reducing agent for the reduction of Pt Cl62- to Pt. As a result, both H2 Pt Cl6 and glucose showed synergy effect on the formation of Pt/Cu bimetallic alloy hollow structure.Finally, by using Cu₂O with different particle sizes and morphologies as template material, D-glucose as a reducing agent and H2 Pt Cl6 as Pt precursor, Pt/Cu₂O hollow structure was obtained via hydrothermal reaction. After removing remained Cu₂O, Pt/Cu bimetallic alloy hollow structure with different size were achieved. The samples showed good electrochemical performance in methanol oxidation reaction. The mass activity of Pt/Cu bimetallic alloy hollow structure, which was applied hexahedral Cu₂O with 40 nm as template, is 2.8 times than the commercial Pt black. The anti-poisoning ability of catalysts prepared by 200 nm Cu₂O template was 2 times than a commercial black Pt. The enhancement of methanol catalytic reaction mainly attributed to the special hollow structure and the synergy between the Pt and Cu.