Electrochemically activated surface reconstruction of OER catalyst by Cr leaching

Abstract

Global demand for energy consumption has been on the rise over the years with globalization and population growth. However, the current usage of fossil fuel as our main energy source raised concerns over the impact on our environment. Hydrogen appears to be the ideal replacement with scalable water electrolysis from renewable energy sources. However, the sluggish kinetics of oxygen evolution reaction (OER) cause it to be expansive and hindered its usage. Therefore it is important to develop an efficient OER catalyst based on first row transition metals to make water oxidation economical. For many years, different transition metal based oxides OER catalyst like perovskite, spinels, layered hydroxides and amorphous oxides/hydroxides have been explored. Recently, surface amorphisation and reconstruction of the catalyst during electrochemical cycling through OER was discovered to boost the OER performance. To engineer and advance our understanding on in-situ surface reconstruction, Cr leaching phenomenon from CoCr2O4 was investigated. Various characterization techniques like CV, CA, ICP, XPS, XAS and TEM techniques were employed to study the active species of OER. The leaching 1.3 Objective and Scope "The present research is concerned with the leaching of Cr from CoCr2O4 to expedite surface reconstruction and in turn enhance its OER performance and provide deeper understanding for application as an OER electrocatalyst.