Mesoporous Cobalt-Molybdenum Oxide as Highly Efficient Anode in Alkaline Water Electrolysis

Abstract

The development of cost-effective, high-performance oxygen evolution reaction (OER) catalysts to replace rare noble metal oxides remains a critical challenge in advancing alkaline water electrolysis (AWE). A mesoporous cobalt-molybdenum oxide (Co–Mo–O) was synthesized via thermal decomposition to evaluate electrochemical anodic performance in alkaline solution. A low potential of 1.6 V vs. RHE at 1000 A m⁻² was recorded under optimized Co–Mo–O catalyst (0.52 M Co²⁺, 0.13 M Mo⁵⁺). Structural analysis revealed porous architecture via SEM, enhancing gas bubble detachment and stress resilience, thereby sustaining catalytic activity. Accelerated durability tests under industrial AWE conditions demonstrated exceptional stability, with minimal weight loss rates (0.1–0.2 mg day⁻¹ at 4000–6000 A m⁻²). Long-term chronopotentiometry confirmed a stable cell potential (~ 2.38 V) over 70 h, with a degradation rate of < 0.006 mg h⁻¹. These results position Co–Mo–O as scalable, noble metal-free catalysts with performance metrics approaching those of precious metal benchmarks, offering significant potential for industrial electrochemical applications.

Graphical Abstract