Electrooxidation of alcohols under the operating conditions of industrial alkaline water electrolysis

Abstract

Hydrogen generation through conventional water electrolysis (CWE) is becoming increasingly prevalent on an industrial scale. However, widespread implementation is partially hampered by the sluggish kinetics of the oxygen evolution reaction (OER) and the severe (energy) costs associated with it. The electrooxidation of alcohols has received great interest within the scientific community as a potential alternative to the OER, leading to the emergence of a novel field known as hybrid water electrolysis (HWE). Nevertheless, while many efforts have been made by multiple stakeholders to give direction to CWE research with the aim of boosting its widespread industrial implementation, the same cannot be said for HWE. In this work, we provide an overview of target performance indicators for industrial alkaline CWE, and we discuss the extent to which the alcohol oxidation reaction (AOR), conducted under similar conditions, reaches those targets. Furthermore, we identify and discuss additional targets required for industrial application of HWE, with specific sections dedicated to the topics of selectivity and circularity of HWE products. In addition to this, we discuss the role that effective reactor design has in combating challenges associated with upscaling of HWE, followed by a description of novel approaches used in the literature. Finally, recommendations are given aiming to direct future research efforts towards industrial application of the AOR with simultaneous hydrogen production.

Keywords: Electrolysis; Alcohol electrooxidation; Alkaline water electrolysis; Hybrid water electrolysis; Industrially relevant conditions.