Ultrathin-Polyaniline-Coated Pt-Ni Alloy Nanooctahedra for the Electrochemical Methanol Oxidation Reaction.

Controlling the morphology and composition of nanocatalysts constructed from metals and conductive polymers has attracted attention owing to their great potential for the development of high-efficiency catalysts for various catalytic applications. Herein, a facile synthetic approach for ultrathin-polyaniline-coated Pt-Ni nanooctahedra (Pt-Ni@PANI hybrids) with controllable PANI shell thicknesses is presented. Pt-Ni nanooctahedra/C catalysts enclosed by PANI shells with thicknesses from 0.6 to 2.4 nm were obtained by fine control over the amount of aniline. The various Pt-Ni@PANI hybrids exhibited electrocatalytic activity toward the methanol oxidation reaction that is highly dependent on the thickness of the PANI shell. Pt-Ni@PANI hybrids with the thinnest PANI shells (0.6 nm) showed markedly improved electrocatalytic performance for the methanol oxidation reaction compared with Pt-Ni@PANI hybrids with thicker PANI shells, Pt-Ni nanooctahedra/C, and commercial Pt/C due to synergistic benefits of ultrathin PANI shells and Pt-Ni alloy.

Highly Porous Au-Pt Bimetallic Urchin-Like Nanocrystals for Efficient Electrochemical Methanol Oxidation.

Highly porous Au-Pt urchin-like bimetallic nanocrystals have been prepared by a one-pot wet-chemical synthesis method. The porosity of urchin-like bimetallic nanocrystals was controlled by amounts of hydrazine used as reductant. The prepared highly porous Au-Pt urchin-like nanocrystals were superior catalysts of electrochemical methanol oxidation due to high porosity and surface active sites by their unique morphology. This approach will pave the way for the design of bimetallic porous materials with unprecedented functions.