Anodic Activation of Prussian Blue Analog Leads to Highly Active Cobalt-Doped Nickel (Oxy)Hydroxide for Organic Oxidation Reactions

Abstract

Water-assisted electrocatalytic oxidation of alcohols into valuable chemicals is a promising strategy to circumvent the sluggish kinetics of water oxidation, while also reducing cell voltage and improving energy efficiency. Recently, transition metal (TM)-based catalysts have been investigated for anodic alcohol oxidation, but success has been limited due to competition from the oxygen evolution reaction (OER) within the working regime. In this study, NiCo-based Prussian blue analog (PBA) was electrochemically activated at the anodic potential to produce a Co-Ni(O)OH active catalyst with a nanosheet-like architecture. This catalyst was further employed for the selective oxidation of benzyl alcohol (PhCH₂OH) to benzoic acid (PhCOOH), achieving a 97 % Faradaic efficiency (FE). The electrochemical activity of Co-Ni(O)OH was also compared with hydrothermally prepared CoNi-LDH, demonstrating that the PBA-derived Co-Ni(O)OH was more effective.

Keywords: Benzyl alcohol oxidation; Electrochemical deposition; Metal oxyhydroxides; Nanosheet structure; Prussian blue analog (PBA).