Nanostructured Intermetallic Nickel Silicide (Pre)Catalyst for Anodic Oxygen Evolution Reaction and Selective Dehydrogenation of Primary Amines
Indranil Mondal, J. Niklas Hausmann, Gonela Vijaykumar, Stefan Mebs, Holger Dau, Matthias Drieß, Prashanth W. Menezes
Abstract
Abstract The development of novel earth‐abundant metal‐based catalysts to accelerate the sluggish oxygen evolution reaction (OER) is crucial for the process of large‐scale production of green hydrogen. To solve this bottleneck, herein, a simple one‐pot colloidal approach is reported to yield crystalline intermetallic nickel silicide (Ni 2 Si), which results in a promising precatalyst for anodic OER. Subsequently, an anodic‐coupled electrosynthesis for the selective oxidation of organic amines (as sacrificial proton donating agents) to value‐added organocyanides is established to boost the cathodic reaction. A partial transformation of the Ni 2 Si intermetallic precatalyst generates a porous nickel(oxy)hydroxide phase modified with oxidic silicon species as unequivocally demonstrated by a combination of quasi in situ Raman and X‐ray absorption spectroscopy as well as ex situ methods. The activated form of the catalyst generates a geometric current density of 100 mA cm −2 at an overpotential (η 100 ) of 348 mV displaying long‐term durability over a week and high efficiency in paired electrolysis.