TRANSITION-METAL BASED ELECTROCATALYSTS FOR WATER ELECTROCHEMICAL OXIDATION

Abstract

The oxygen evolution reaction (OER) is fundamental to the operation of electrochemical devices such as rechargeable metal-air batteries and water splitting systems. The greatest challenge of OER is its sluggish kinetics, which can only be mitigated by the development of effective catalysts. Among the catalysts explored to date, nickel-based compounds have shown the best performance in OER catalysis. However, the continuing improvement of Ni-based catalysts remains high on the research agenda of oxygen electrocatalysis. The thesis presents several designs of nickel-based electrocatalysts with good OER performance in alkaline solution. These catalysts include supported and unsupported Ni in the form of hydroxide and sulfide. These catalysts were extensively characterized; and evaluated by standard electrochemical methods. In short, the three studies in this thesis project confirmed the value of anionic substitution as a catalyst modification technique which promotes the PCET mechanism in OER without the loss of metal catalytic centers.