Dynamically Adaptive Bubbling for Upgrading Oxygen Evolution Reaction Using Lamellar Fern-Like Alloy Aerogel Self-Standing Electrodes.

Abstract

Adopting renewable electricity to produce "green" hydrogen has been a critical challenge because at a high current density the mass transfer capability of most catalytic electrodes deteriorates significantly. Herein, a unique lamellar fern-like alloy aerogel (LFA) electrode, showing a unique dynamically adaptive bubbling capability and can effectively avoid stress concentration caused by bubble aggregation is reported. The LFA electrode is intrinsically highly catalytic-active and shows a highly porous, resilient, hierarchically ordered, and well-percolated conductive network. It not only shows superior gas evacuation capability but also exhibits significantly improved stability at high current densities, showing the record lowest oxygen evolution reaction (OER) overpotential of 244mV at 1000mA cm-2 and stably over 6000 h. With the merits of mechanical robustness, excellent electron transport, and efficient bubble evacuation, LFA can be self-standing catalytic electrode andgas diffusion layers in anion-exchange-membrane water electrolysis (AEMWE), which can achieve 3000 mA cm-2 at a low voltage of 1.88V and can sustain stable electrolysis at 2000 mA cm-2 for over 1300 h. This strategy can be extended to various gas evolution reactions as a general design rule for multiphase catalysis applications.