Investigation of zeolite supported platinum electrocatalyst for electrochemical oxidation of small organic species

Abstract

Zeolite supported Pt electrocatalysts, made by ion exchange method using Pt/Y type zeolite, have been investigated to determine Pt electrochemical activity of HCOOH and CH3OH oxidation using the cyclic voltammetry (CV) and the extended X-ray adsorption fine structure (EXAFS) techniques. The study reveals that the introduction of excess H+ ions during electrocatalyst pre-treatment could enhance electrochemical reaction on Pt surface due to higher Pt dispersion, regardless of zeolite being a direct current electronic conducting insulator. Two possible conduction pathways might contribute to the electrocatalytic reaction on Pt surface with Pt particle size and loading: (1) hydrogen atoms/H+ ions spillover through zeolite framework and at the electrode and solution interface; (2) surface mobility of adsorbed species on electrode surface. The water may act as a carrier in assisting the migration of the H+ ions throughout zeolite channels to facilitate the charger and electron transfer in such an electrical system.