Co-Electroless Deposition of Pt-M Bimetallic Alloyed Catalysts for Methanol Oxidation

Abstract

Direct methanol fuel cells exhibit great promise as portable sources of power. A primary issue, however, is that the platinum catalyst used is readily poisoned by CO that is formed during the methanol oxidation reaction. Further, reducing the amount of Pt used is crucial to reducing the cost of direct methanol fuel cells. A straightforward way to address both issues is to synthesize bimetallic catalysts with Pt and a secondary metal that provides the necessary –OH groups to remove CO from Pt. Co-precipitation and co-impregnation methods have traditionally been used for the synthesis of metallic and bimetallic catalysts. These methods, however, afford little control over nanoparticle composition, size, and spacing. Electroless deposition solves these issues by allowing precise compositional, size, and, when paired with strong electrostatic adsorption, spacing control. The Monnier group has developed a continuous deposition method that produces composition-controlled bimetallic alloyed catalysts on a seeded support.1 Mehrabadi et al. 2 demonstrated previously that Ru deposited by electroless deposition onto a Pt/C support was superior to commercial PtRu catalysts for methanol oxidation. Bimetallic and trimetallic catalyst syntheses have also been demonstrated. In this work, we synthesize Pt-Co and Pt-Ni bimetallic catalysts with controlled compositions. We find that specific compositions (Pt3Ni and Pt2Co) exhibit significantly improved mass activity. This talk will discuss the synthesis and characterization of these bimetallic alloyed catalysts as well as the activity for methanol oxidation observed. Tate, G., Kenvin, A., Diao, W., Monnier, J. R., “Preparation of Pt-containing bimetallic and trimetallic catalysts using continuous electroless deposition methods,” Catalysis Today, (2018)Tavakoli Mehrabadi, B.A., Catalysis Today, https://doi.org/10.1016/j.cattod.2018.11.042