Ni-W solid solution alloy as a high-performance catalyst for hydrazine electrooxidation

Abstract

In the development of earth-abundant anodic electrocatalysts for direct hydrazine fuel cells (DHzFCs), one of the daunting challenges is to improve the electrocatalytic activity for the hydrazine oxidation reaction (HzOR) while effectively suppressing the non-faradaic decomposition of hydrazine. Herein, we present the synthesis of a Ni foam-supported Ni-W solid solution alloy (SSA) catalyst through a solvothermal approach followed by reductive calcination. Our study demonstrates that the Ni-W solid solution alloy outperforms intermetallic compound in simultaneously enhancing the electrocatalytic activity and inhibiting the non-faradaic hydrazine decomposition under alkaline conditions. Benefiting from its enhanced intrinsic activity, the open porous architecture, and good electrical conductivity, the Ni95W5(SSA)/NF catalyst has exhibited remarkable activity, good stability, and an impressive selectivity nearing 100 % towards the 4-electron hydrazine electrooxidation, surpassing most reported Ni-based alloy catalysts. Inspired by the exceptional catalytic performance, we have subsequently constructed a DHzFC utilizing Ni95W5(SSA) as the anode catalyst, and evaluated its performance under ambient temperature.