Boosting oxygen electrode efficiency using engineered CuO/Cu₂O/C nanostructure

Abstract

The key ongoing challenge is to design and develop effective and inexpensive oxygen reduction reaction (ORR) catalysts to replace Pt‐based ones for commercial use in fuel cells. Owing to its abundance and tunable electronic properties, in the current work, the synthesis of highly dispersed mixed valent copper oxide electrocatalyst is reported. The EC exhibits a high mass activity of 9.8 mA mg−1 and a high current density of 5.3 mA cm−2 in contrast to the benchmark (20 wt%) Pt/C catalyst in a 0.1‐M KOH solution for ORR. The significantly high electrochemical activity at the cathode is believed to be due to the presence of the Cu(II)/Cu(I) redox pair. Furthermore, the catalyst has been shown to be highly stable, maintaining a high current retention of 78% for up to 24 h. Furthermore, the engineered material is also active for the oxygen evolution reaction, making it a viable replacement for conventional Pt/C in alkaline fuel cells.