title: High Catalytic Activity of Amorphous Ir-Pi for Oxygen Evolution Reaction.
abstract: Large-scale production of hydrogen gas by water electrolysis is hindered by the sluggish kinetics of oxygen evolution reaction (OER) at the anode. The development of a highly active and stable catalyst for OER is a challenging task. Electrochemically prepared amorphous metal-based catalysts have gained wide attention after the recent discovery of a cobalt-phosphate (Co-Pi) catalyst. Herein, an amorphous iridium-phosphate (Ir-Pi) is investigated as an oxygen evolution catalyst. The catalyst is prepared by the anodic polarization of carbon paper electrodes in neutral phosphate buffer solutions containing IrCl3. The Ir-Pi film deposited on the substrate has significant amounts of phosphate and Ir centers in an oxidation state higher than +4. Phosphate plays a significant role in the deposition of the catalyst and also in its activity toward OER. The onset potential of OER on the Ir-Pi is about 150 mV lower in comparison with the Co-Pi under identical experimental conditions. Thus, Ir-Pi is a promising catalyst for electrochemical oxidation of water.
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India.
authors.forename: Ahamed
authors.initials: A
authors.lastname: Irshad
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-560012, India.
authors.forename: Nookala
authors.initials: N
authors.lastname: Munichandraiah
keywords: Ir-Pi catalyst; amorphous catalysts; electrochemical deposition; electrolysis of water; hydrogen generation; phosphate buffer; water oxidation