Double-Metal-Ion-Exchanged Mesoporous Zeolite as an Efficient Electrocatalyst for Alkaline Water Oxidation: Synergy between Ni–Cu and Their Contents in Catalytic Activity Enhancement

Abstract

The kinetics of total water splitting is mostly hampered by the sluggish oxygen evolution reaction (OER) at the anode of the electrolyzer. Herein, we focus on the design of a cost-effective porous OER catalyst for efficient water to fuel conversion. A simple metal-ion-exchange protocol is adapted to implant electroactive metal centers in the mesoporous architecture of Zeolite Socony Mobil-5 (ZSM-5). OER-active Ni is incorporated as catalytic sites in the mesoporous ZSM-5. Further, simultaneous incorporation of both Ni2+ and Cu2+ into the mesoporous ZSM-5 (Meso-Z) matrix significantly boost the OER catalytic activity. The optimization of Ni and Cu contents (1.04 wt % Ni and 0.44 wt % Cu) in the catalyst is found to be essential to achieve high catalytic activity. The Cu content influences the onset potential, and the Ni content determines the catalytic current during OER. Among developed catalysts, Ni2Cu1-Meso-Z offers the best performance even better than the state-of-art OER catalyst IrO2. Ni2Cu1-Meso-Z ...