Application of Black Pearl carbon-supported WO 3 nanostructures as hybrid carriers for electrocatalytic RuSe x nanoparticles

Abstract

RuSe x electrocatalytic nanoparticles were deposited onto hybrid carriers composed of Black Pearl carbon-supported tungsten oxide; and the resulting system's electrochemical activity was investigated during oxygen reduction reaction. The tungsten oxide-utilizing and RuSe x nanoparticle-containing materials were characterized using transmission electron microscopy, X-ray diffraction and electrochemical diagnostic techniques such as cyclic voltammetry and rotating ring-disk voltammetry. Application of Black Pearl carbon carriers modified with ultra-thin films of WO 3 as matrices (supports) for RuSe x catalytic centers results during electroreduction of oxygen in 0.5 mol dm −3 H 2SO 4 (under rotating disk voltammetric conditions) in the potential shift of ca. 70 mV towards more positive values relative to the behavior of the analogous WO 3-free system. Also the percent formation (at ring in the rotating ring-disk voltammetry) of the undesirable hydrogen peroxide has been decreased approximately twice by utilizing WO 3-modified carbon carriers. The results are consistent with the bifunctional mechanism in which oxygen reduction is initiated at RuSe x centers and the hydrogen peroxide intermediate is reductively decomposed at reactive WO 3-modified Black Pearl supports. The electrocatalytic activity of the system utilizing WO 3-modified Black Pearl supports has been basically unchanged upon addition of acetic acid, formic acid or methyl formate to the sulfuric acid supporting electrolyte.