A Multi‐Doped Electrocatalyst for Efficient Hydrazine Oxidation

Abstract

We report an efficient electrocatalyst for the oxidation of hydrazine,apromising fuel for fuel cells and an important analyte for health and environmental monitoring. To design this material, we emulated natural nitrogen-cycle enzymes,f ocusing on designing ac ooperative,m ulti-doped active site.T he catalytic oxidation occurs on Fe 2 MoC nanoparticles and on edge-positioned nitrogen dopants,a ll welldispersed on ah ierarchically porous,g raphitic carbon matrix that provides active site exposure to mass-transfer and charge flow. The new catalyst is the first carbide with HzOR activity.It operates at the most negative onset potentials reported for carbon-based HzOR catalysts at pH 14 (0.28 Vvs. RHE), and has good-to-excellent activity at pH values down to 0. It shows high faradaic efficiency for oxidation to N 2 (3.6 e À /N 2 H 4 ), and is perfectly stable for at least 2000 cycles. Conflict of interestTheauthors declare no conflict of interest.

Dissolution-regrowth of hierarchical Fe-Dy oxide modulates the electronic structure of nickel-organic frameworks as highly active and stable water splitting electrocatalysts

“…S2b. The XRD data of FeDy@MOF-Ni, Fe@MOF-Ni, and Dy@MOF-Ni match well with the diffraction peaks of Dy2O3 (JCPDS: 43-1006) [24,25] and Fe2O3 (JCPDS: 39-1346). The crystal structure of MOF-Ni was gradually destroyed during the FeDy@MOF-Ni synthesis due to ion exchange resulting in structural deformation [26,27].…”

Atomically Dispersed Semimetallic Selenium on Porous Carbon Membrane as an Electrode for Hydrazine Fuel Cells

“…Hydrazine is avery promising liquid fuel candidate for fuel cells due to its high theoretical electromotive force (1.56 V), high power density,a nd environmentally benign byproducts [25] (Figure 3a). Hydrazine is avery promising liquid fuel candidate for fuel cells due to its high theoretical electromotive force (1.56 V), high power density,a nd environmentally benign byproducts [25] (Figure 3a).…”

Atomically Dispersed Semimetallic Selenium on Porous Carbon Membrane as an Electrode for Hydrazine Fuel Cells

“…In control experiments, it is demonstrated that commercial nanostructured Se powder (SEM and XRD characterizations were provided in Figure S22) has no electroactivity for HzOR; N‐doped porous carbon membrane without Se doping (NCM‐1000, structural characterizations were provided in Figure S23,24) has negligible HzOR activity, which reflected by a very high onset peak potential (0.6 V vs. RHE) and low peak current intensity (5.6 mA cm −2 ). The electrochemical active surface area (ECSA) of SeNCM‐1000 was determined to be 1175 cm 2 by double layer capacitance method (Figure S25), which is two orders of magnitudes higher than that of NCM‐1000 (57.5 cm 2 ). This investigation suggests that the existence of atomically dispersed Se could dramatically enhance the ECSA of SeNCM‐1000 thereby exhibiting outstanding catalytic activity toward HzOR.…”

“…To demonstrate the practical applications of the newly designed materials, we directly utilized SeNCM‐ x as electrodes without the need of a binder for HzOR. Hydrazine is a very promising liquid fuel candidate for fuel cells due to its high theoretical electromotive force (1.56 V), high power density, and environmentally benign byproducts (Figure a). The cyclic voltammetry (CV) curves of SeNCM‐ x exhibited obvious oxidation peaks in 1 m KOH solution with 100 m m N 2 H 4 , but no peaks in the pure KOH solution (Figure b).…”