Acta Chim. Sinica ›› 2017, Vol. 75 ›› Issue (2): 237-240.DOI: 10.6023/A16090460 Previous Articles     Next Articles

Special Issue: 先进电池材料

Article

Pt-Ni-P/Ti蜂窝状电极的制备及其催化甲醇氧化性能研究

陶熊新, 李莉, 齐学强, 魏子栋   

  1. 重庆大学化学化工学院 重庆 400044
  • 收稿日期:2016-09-01 修回日期:2016-12-19 出版日期:2017-02-15 发布日期:2016-12-20
  • 通讯作者: 魏子栋,E-mail:zdwei@cqu.edu.cn;Tel:023-65105161 E-mail:zdwei@cqu.edu.cn
  • 基金资助:

    项目受国家自然科学基金(Nos.21376283,21376284)资助.

Preparation and Electrochemical Properties of Honeycomb-like Pt-Ni-P/Ti Electrode for Methanol Oxidation

Tao Xiongxin, Li Li, Qi Xueqiang, Wei Zidong   

  1. College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044
  • Received:2016-09-01 Revised:2016-12-19 Online:2017-02-15 Published:2016-12-20
  • Contact: 10.6023/A16090460 E-mail:zdwei@cqu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21376283 and 21376284).

A honeycomb-like metallic catalyst (Pt-Ni-P/Ti) supported on a Ti sheet was prepared by electrodeposition-displacement method. The Ni-P amorphous alloy was first electrodeposited on the Ti substrate, and then replaced by displacement of Ni in amorphous Ni-P with H2PtCl6. The morphology and methanol oxidation performance of the prepared catalyst were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), anodic linear sweep voltammetry (LSV), cyclic voltammetry (CV), and the anodic stripping of a pre-adsorbed CO monolayer. The SEM results show that the Pt-Ni-P nanoparticles obtained by displacement of Ni in amorphous Ni-P with H2PtCl6 had a honeycomb-like porous structure, while the Pt-Ni nanoparticles had a wheat-like structure. The formation of the honeycomb-like porous structure can be explained by the so-called "out-situ dissolution-deposition mechanism", in which the metallic Ni in Ni-P/Ti electrode preferentially dissolve to form pore structure and release electron. The released electrons can be captured by the PtCl62- ion adsorbed on the surface of Ni-P and reduced on the surface of Ni-P to form Pt shell, thereby forming a honeycomb-like pore structure. For the Pt-Ni/Ti electrode, the formation of wheat-like structure Pt-Ni nanoparticles can be explained by a so-called "in-situ dissolution-deposition mechanism", in which the Pt replacement reaction can only occur at the surface of Ni, and the replacement Pt monolayer can prevent the further chemical substitution of Pt on Ni, thereby forming a wheat-like structure. The electrochemical test results show that the methanol oxidation and CO oxidation onset potential on Pt-Ni-P/Ti electrode in alkaline solution is more negative than that on Pt-Ni/Ti electrode, indicating that P incorporation can significantly enhance the methanol oxidation activity and CO-tolerance. Moreover, the unique honeycomb-like porous structure is beneficial to the fast mass transportation during the catalytic reaction. The combination of compositionally and geometrically favorable factors provides a new avenue to design new electrocatalysts with excellent methanol oxidation activity and CO-tolerance.

Key words: direct methanol fuel cell, electrodeposition-replacement, electrocatalysis, methanol oxidation