Platinum–Ruthenium Nanotubes and Platinum–Ruthenium Coated Copper Nanowires As Efficient Catalysts for Electro-Oxidation of Methanol

• Published in: ACS catalysis 2015-03, Vol.5 (3), p.1468-1474
• Main Authors: Zheng, Jie, Cullen, David A, Forest, Robert V, Wittkopf, Jarrid A, Zhuang, Zhongbin, Sheng, Wenchao, Chen, Jingguang G, Yan, Yushan
• Format: Article
• Language: English
• Subjects: 30 DIRECT ENERGY CONVERSION; electrocatalysis; MATERIALS SCIENCE; methanol fuel cells; methanol oxidation reaction; one-dimensional structure; platinum−ruthenium
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/cs501449y

The sluggish kinetics of methanol oxidation reaction (MOR) is a major barrier to the commercialization of direct methanol fuel cells (DMFCs). In this work, we report a facile synthesis of platinum–ruthenium nanotubes (PtRuNTs) and platinum–ruthenium-coated copper nanowires (PtRu/CuNWs) by galvanic displacement reaction using copper nanowires as a template. The PtRu compositional effect on MOR is investigated; the optimum Pt/Ru bulk atomic ratio is about 4 and surface atomic ratio about 1 for both PtRuNTs and PtRu/CuNWs. Enhanced specific MOR activities are observed on both PtRuNTs and PtRu/CuNWs compared with the benchmark commercial carbon-supported PtRu catalyst (PtRu/C, Hispec 12100). X-ray photoelectron spectroscopy (XPS) reveals a larger extent of electron transfer from Ru to Pt on PtRu/CuNWs, which may lead to a modification of the d-band center of Pt and consequently a weaker bonding of CO (the poisoning intermediate) on Pt and a higher MOR activity on PtRu/CuNWs.