Oxygen vacancy enriched CeOx supported CuNC aerogel for oxygen evolution reaction in alkaline media

Abstract

Developing highly efficient and stable oxygen evolution reaction (OER) catalysts is crucial for large-scale hydrogen production via water electrolysis. However, most transition-metal-based catalysts still suffer from insufficient active sites, sluggish kinetics, and poor long-term stability. Herein, we design and synthesize an oxygen-vacancy-rich CeO_x supported on CuNC (NC: nitrogen-doped carbon) aerogel (CuNC@CeO_x) as an advanced OER catalyst. The abundant oxygen vacancies in CeO_x, coupled with the hierarchical porous structure of CuNC aerogel, synergistically enhance the electrocatalytic activity and stability. In 1 M KOH, the CuNC@CeO_x aerogel exhibits a low overpotential of 326.4 mV at 10 mA cm⁻² and a small Tafel slope of 141.50 mV dec⁻¹, outperforming the commercial RuO₂ benchmark. Furthermore, it maintains a stable current density even after 250 000 seconds, demonstrating exceptional long-term durability. This work provides a facile and effective strategy for constructing metal-aerogel-based electrocatalysts with abundant oxygen vacancies, offering new insights into the design of high-performance OER catalysts.