Versatile LaCo0.6Ni0.4O3-δ Nanofiber Membrane for High Performance Oxygen Electrocatalysis over a Wide Temperature Range

Small. 2024 Dec 24:e2409051. doi: 10.1002/smll.202409051. Online ahead of print.

Abstract

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are key processes in numerous oxygen-involved applications over a wide temperature range. Despite advances in nanofiber engineering to increase active site density and catalytic efficiency for ORR/OER, conventional electrode fabrication methods often compromise the integrity of nanofibrous structures. Herein, a robust strategy is presented for the fabrication of LaCo0.6Ni0.4O3-δ (LCN) nanofibrous membranes using optimized electrospinning techniques. This approach achieves high specific surface area, increased porosity, rapid mass transport, and precise control of morphology and thickness. The resulting LCN nanofibers exhibit exceptional ORR and OER catalytic activity at room temperature, rivaling commercial Pt/C and RuO₂ catalysts. Moreover, in solid oxide cells (SOCs) operating at elevated temperatures, LCN nanofibrous membranes deliver remarkable ORR and OER performance, with a peak power density of 0.802 W cm- 2 at 700 °C and excellent stability over 180 h. These results highlight the potential of nanofibrous perovskite catalysts for practical oxygen electrocatalytic applications and demonstrate that the LCN nanofibrous membrane, combined with a self-assembly approach, exploits on the advantages of high porosity and specific surface area. This work opens up new avenues for the use of nanofibrous electrodes in a wide temperature range.

Keywords: LaCo0.6Ni0.4O3‐δ; nanofibrous membrane electrode; oxygen reduction/evolution reaction; solid oxide cells; wide temperature range application.