Three-dimensionally interconnected titanium foam anode for an energy-efficient zero gap-type chlor-alkali electrolyzer

Abstract

© 2019 Hydrogen Energy Publications LLC Chlor-alkali (CA)electrolysis is used to generate high-purity (>99.999%)chlorine and hydrogen gas, in addition to caustic soda (NaOH). Despite its usefulness, the electrochemical process consumes a large amount of electric energy. In this study, Ti foam was employed as the anode, and its morphological and electrochemical properties were compared with those of a dimensionally stable anode (DSA), which is commonly used in CA industries. The morphology and chemical composition of these anodes were examined with scanning electron microscopy (SEM). Porosity was determined by mercury porosimetry. Surface elemental characterization and crystallographic analysis of the electrodes were performed using X-ray photoelectron spectroscopy (XPS)and X-ray diffraction (XRD), respectively. The electrochemical performances of the cells employing each electrode were evaluated in terms of chlorine and hydrogen production rate, energy consumption, and hydrogen current efficiency. Finally, chronopotentiometry was carried out to verify the potential of the Ti foam as an energy-efficient anode