Electrocatalytic and corrosion behaviour of tungsten carbide in near-neutral pH electrolytes

Abstract

This paper examines the electrochemical and electrocatalytic behaviour of tungsten carbide at ambient temperature and at near to neutral pH conditions. The electrocatalytic oxidation of hydrogen, formate and lactate is investigated as a function of the composition of the catalyst material, and of the composition and pH of the used electrolyte solutions. It is demonstrated that for the oxidation of hydrogen, different surface and bulk properties are decisive than for the oxidation of formate and lactate. A major problem of tungsten carbide is its stability in aqueous, pH neutral environments, in which noticeable corrosion processes take place. The individual corrosion rates strongly depend on the electrolyte composition and pH, and on the presence of reducing agents. © 2008 Elsevier B.V. All rights reserved.