Core-shell FTO@CoO nanoparticles as active and stable anode catalysts for acidic oxygen evolution reaction and proton exchange membrane water electrolysis

The development of active and stable non-noble metal based anode catalysts is challenging and critical for further advancement of acidic water splitting and proton exchange membrane water electrolysis (PEMWE) for green hydrogen production. Enhancing the electrochemical stability of active materials through composition engineering is a promising approach. Co 3+ -lean and oxygen vacancy free Co 3 O 4 was developed and dispersed on acid-resistant conductive F-doped tin oxide nanoparticles, FTO@Co 3 O 4 , as an active and a stable anode catalyst for the catalyzation of the oxygen evolution reaction (OER) in acidic media. It achieved an overpotential of 511 mV at 10 mA cm −2 and remained stable with a potential increase of only 2% after a 21.5 hour OER operation at 10 mA cm −2 in 0.5 M H 2 SO 4 . When serving as an anode catalyst in PEMWE, it generated a current density of 0.205 A cm −2 at 2 V at room temperature and maintained stability with a cell voltage increase of 5.8% after 21.5 hour operation at 10 mA cm −2 . An anode catalyst, FTO-dispersed Co 3+ -lean and O vac -free OER-active Co 3 O 4 , was developed for the high performance acidic oxygen evolution reaction and proton exchange membrane water electrolysis.