Electrocatalysts for value-added electrolysis coupled with hydrogen evolution

Abstract

A green and sustainable energy route to produce hydrogen and other oxidation products with maximized values deserves more attention than common water electrolysis. The search for alternative pathways is motivated not only by the need to reduce electricity consumption but also by the desire to produce valuable chemicals sustainably. Value-added anodic reactions (VAARs) can replace the kinetically sluggish oxygen evolution reaction (OER) in electrochemical energy conversion systems to pair with cathodic hydrogen evolution reaction (HER) and fulfil the growing demand for green hydrogen and chemicals. In this review, electrocatalysts for value-added conversion reactions such as iodide oxidation reaction (IOR), poly-alcohol oxidation reaction (AOR), chitin oxidation reaction (COR), urea oxidation reaction (UOR), and hydrazine oxidation reaction (HzOR) are systematically summarized. Electrocatalysts, such as single atom catalysts (SACs), transition metal oxides/hydroxides, heteroatom doped carbon support, and self-supported mixed alloy oxide, that promote various value-added anodic reactions are summarized. Finally, an outlook on the future challenge in new value-added electrolysis is proposed.