Deep Reconstruction of RuPdO_x Hollow Nanofibers for Efficient Electrocatalytic Hydrazine Oxidation-Assisted Hydrogen Production.

Abstract

Manipulating the reconstruction of a heterostructured material is highly desirable to achieve high-performance electrocatalytic performance. Here, an in situ reconstruction of RuPdO_x hollow nanofibers (HNFs) is presented to generate RuO₂/Pd from both the electrochemical and chemical reconstruction processes. The reconstructed catalyst is highly efficient for both hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER) at industrial-grade current densities, significantly outperforming the benchmark Pt/C catalyst. Furthermore, it maintains a record-breaking durability of 500 h for HzOR at 1 A cm^-2. Remarkably, with the catalyst as electrodes, a two-electrode overall hydrazine splitting (OHzS) cell is constructed, which requires only 0.263 kWh of electricity to produce 1 m³ H₂ at 100 mA cm^-2, significantly lower than that in overall water splitting (OWS) system (4.286 kWh m^-3 H₂), exhibiting an exceptional energy-saving H₂ production property. Density functional theory (DFT) calculations reveal an efficient electron transfer from Pd to RuO₂ at their interface from the reconstruction of RuPdO_x HNFs, which regulates the local electronic environment of atoms, modulates the adsorption and desorption for intermediates, and reduces the energy barriers for enhancing the electrocatalytic process. This study offers a robust reconstruction strategy for the design of electrocatalysts that exhibit superior efficiency in energy conversion devices.