Bifunctional Ultrathin RhRu_0.5‐Alloy Nanowire Electrocatalysts for Hydrazine‐Assisted Water Splitting

Abstract

Hydrazine‐assisted water electrolysis offers a feasible path for low‐voltage green hydrogen production. Herein, the design and synthesis of ultrathin RhRu0.5‐alloy wavy nanowires as bifunctional electrocatalysts for both the anodic hydrazine oxidation reaction (HzOR) and the cathodic hydrogen evolution reaction (HER) is reported. It is shown that the RhRu0.5‐alloy wavy nanowires can achieve complete electrooxidation of hydrazine with a low overpotential and high mass activity, as well as improved performance for the HER. The resulting RhRu0.5 bifunctional electrocatalysts enable, high performance hydrazine‐assisted water electrolysis delivering a current density of 100 mA cm−2 at an ultralow cell voltage of 54 mV and a high current density of 853 mA cm−2 at a cell voltage of 0.6 V. The RhRu0.5 electrocatalysts further demonstrate a stable operation at a high current density of 100 mA cm−2 for 80 hours of testing period with little irreversible degradation. The overall performance greatly exceeds that of the previously reported hydrazine‐assisted water electrolyzers, offering a pathway for efficiently converting hazardous hydrazine into molecular hydrogen.

Regulating Ru active sites by Pd alloying to significantly enhance hydrazine oxidation for energy-saving hydrogen production

“…As shown in Fig. 3D, it can be observed from the LSV curve that RuPd/C merely needs ultralow potentials (−77.9 and −49.1 mV) to achieve 10 and 100 mA cm −2 , superior to Pt/C (134 and 233.6 mV), Ru/C (−47.3 and 142.2 mV) and Pd/C (155.4 and 339.3 mV), also overmatching recently reported Ru, 18,19,37,45,46 Rh, 47,48 Ir, 20 alloys, 23,49–53 and even self-supported materials, 3,5,54–56 demonstrating the exceptionally superior HzOR activity on RuPd/C. These reflect the significantly enhanced HzOR activity by alloying and the great advantage in replacing the OER for energy-efficient H 2 generation.…”

Constructing CoO/Mo2C Heterostructures with Interfacial Electron Redistribution Induced by Work Functions for Boosting Overall Water Splitting

“…[29] Benefiting from charge transfer at the interface, CoO/Mo 2 C behaves a higher density state near the Fermi level compared to pure CoO and Mo 2 C, which suggests the high electronic conductivity and accelerating catalytic kinetics (Figure 4d). [30] The HER process is involving adsorption, dissociation, and H 2 desorption and the corresponding models are shown in Figure 4e. Moreover, we calculated the free energies of the H 2 O dissociation, and H 2 desorption on different catalysts' surfaces in Figure 4f.…”

Au–Rh2P Mesoporous Nanotubes for the Hydrogen Evolution Reaction and Hydrazine Oxidation Electrooxidation

“…5,6 Additionally, hydrazine-containing wastewater is widely produced in chemical and pharmaceutical industries, which is carcinogenic and toxic. 7,8 Therefore, it is highly economical to develop hydrazine-assisted water splitting for hydrogen production, and the key lies in the preparation of bifunctional catalysts with excellent electrocatalytic activity and stability for both the HzOR and hydrogen evolution reaction (HER).…”

“…Hydrogen has received abundant interest as a clean energy source due to no carbon emission and high energy density. Nowadays, water electrolysis is regarded as an attractive method to produce hydrogen due to its environmental friendliness and ease of operation. , However, sluggish oxygen evolution reaction limits its large-scale application. , The use of thermodynamically more favorable hydrazine oxidation reaction (HzOR) to replace oxygen evolution reaction (OER) is a promising strategy for energy-saving hydrogen production because of the much lower oxidation potential of HzOR (−0.33 V) and more safety for hydrogen production. , Additionally, hydrazine-containing wastewater is widely produced in chemical and pharmaceutical industries, which is carcinogenic and toxic. , Therefore, it is highly economical to develop hydrazine-assisted water splitting for hydrogen production, and the key lies in the preparation of bifunctional catalysts with excellent electrocatalytic activity and stability for both the HzOR and hydrogen evolution reaction (HER).…”