Morphology and Microstructure of IrxSi1-xO2 Oxides as Anodic Electrocatalyst for Electrosynthesis of Dinitrogen Pentoxide

Abstract

The anodes of IrxSi1-xO2/Ti (x= 0.2~1) were prepared by thermal decomposition of non-aqueous solution of iridium chloride (IrCl3) and tetraethoxysilane (TEOS). The microstructure and surface morphology of the IrxSi1-xO2 coatings were characterized by XRD and SEM. A large amount of fine crystallites aggregated on the surface of coatings to form a porous structure with a range of particle size of 15-18nm. The particle size decreased firstly and then increased with increase of silica content and received a minimum value at the Ir0.6Si0.4O2 coatings. The electrochemical characterization determined by cyclic voltammetry (CV) indicated that the IrxSi1-xO2 coating with x=0.6 showed a maximum surface charge (q). The experiments of electrochemical synthesis of N2O5 from N2O4 in nitric acid indicated that the Ir0.6Si0.4O2 coating had the best electrocatalytic performance.