Mesoporous Nickel/Nickel Hydroxide Catalyst Using Liquid Crystal Template for Ethanol Oxidation in Alkaline Solution

Abstract

A mesoporous nickel/nickel hydroxide (Ni/Ni(OH)2) catalyst was prepared by chemical reduction of nickel ions dissolved in the interstitial spaces of the hexagonal liquid crystalline template of the non-ionic surfactant Brij56. The physicochemical characterizations of the catalyst performed by surface area analyzer, X-ray diffraction, scanning and transmission electron microscopes suggests formation of a mesoporous crystalline structure of Ni/Ni(OH)2 with a surface area of 90 ± 3 m2/g. This is an order of magnitude higher than that for nickel particles formed without surfactant template. The electrochemical behavior and ethanol oxidation catalytic activity of the mesoporous Ni/Ni(OH)2 catalyst was investigated by cyclic voltammetry and chronoamperometry techniques in alkaline medium. The activity of the mesoporous Ni/Ni(OH)2 catalyst shows a more than 10-fold increase compared to bulk nickel catalyst (formed without surfactant) consistent with the enhancement of electro-active surface area. Bulk liquid-crystal template deposition offers a reproducible platform to fabricate mesoporous metal/oxides/hydroxides with enhanced electrocatalytic performance.