Enhanced electrocatalytic performance triggered by atomically bridged boron nitride between palladium nanoparticles and carbon fibers in gas-diffusion electrodes

Abstract

Significant reduction of the amount of precious metals in catalysts is a major challenge. We report the synthesis of high-performance carbon paper-boron nitride-palladium (CP-BN-Pd) electrocatalytic electrodes. The nanocatalysts consist of Pd nanoparticles of 5 nm supported on an ultrathin BN film prepared by atomic layer deposition (ALD), covering the microfibers of gas-diffusion electrodes (GDL). These electrodes present significantly enhanced electrocatalytic performance towards oxygen reduction (ORR) and C2 alcohols oxidation reactions and outperform the reported data for those alcohols in alkaline media, reaching a peak current of 17 amps/mgPd in 1 M NaOH + 1 M ethanol. The ageing tests reveal excellent stability of the electrochemically active surface area even after 1000 cycles, and the ethanol oxidation activity shows negligible decay of 1% whereas commercial Pd/C show prominent decay of 44%. The use of this heterogeneous active interface opens a new route for the development of efficient and low-metal content nanocatalysts.