The discovery of stable and noble-metal-free catalysts toward efficient electrochemical reduction of nitrogen (N ) to ammonia (NH ) is highly desired and significantly critical for the earth nitrogen cycle. Here, based on the theoretical predictions, MoS is first utilized to catalyze the N reduction reaction (NRR) under room temperature and atmospheric pressure. Electrochemical tests reveal that such catalyst achieves a high Faradaic efficiency (1.17%) and NH yield (8.08 × 10 mol s cm ) at -0.5 V versus reversible hydrogen electrode in 0.1 m Na SO . Even in acidic conditions, where strong hydrogen evolution reaction occurs, MoS is still active for the NRR. This work represents an important addition to the growing family of transition-metal-based catalysts with advanced performance in NRR.
The industrial artificial fixation of atmospheric N2 to NH3 is carried out using the Haber–Bosch process that is not only energy‐intensive but emits large amounts of greenhouse gas. Electrochemical reduction offers an environmentally benign and sustainable alternative for NH3 synthesis. Although Mo‐dependent nitrogenases and molecular complexes effectively catalyze the N2 fixation at ambient conditions, the development of a Mo‐based nanocatalyst for highly performance electrochemical N2 fixation still remains a key challenge. Here, greatly boosted electrocatalytic N2 reduction to NH3 with excellent selectivity by defect‐rich MoS2 nanoflowers is reported. In 0.1 m Na2SO4, this catalyst attains a high Faradic efficiency of 8.34% and a high NH3 yield of 29.28 µg h−1 mg−1cat. at −0.40 V versus reversible hydrogen electrode, much larger than those of defect‐free counterpart (2.18% and 13.41 µg h−1 mg−1cat.), with strong electrochemical stability. Density functional theory calculations show that the potential determining step has a lower energy barrier (0.60 eV) for defect‐rich catalyst than that of defect‐free one (0.68 eV).
Titanium‐based catalysts are needed to achieve electrocatalytic N2 reduction to NH3 with a large NH3 yield and a high Faradaic efficiency (FE). One of the cheapest and most abundant metals on earth, iron, is an effective dopant for greatly improving the nitrogen reduction reaction (NRR) performance of TiO2 nanoparticles in ambient N2‐to‐NH3 conversion. In 0.5 m LiClO4, Fe‐doped TiO2 catalyst attains a high FE of 25.6 % and a large NH3 yield of 25.47 μg h−1 mgcat−1 at −0.40 V versus a reversible hydrogen electrode. This performance compares favorably to those of all previously reported titanium‐ and iron‐based NRR electrocatalysts in aqueous media. The catalytic mechanism is further probed with theoretical calculations.
The detection of glucose has important significance in clinical medicine and food industry, especially in the diagnosis of diabetes. In recent years, electrochemical non-enzymatic glucose sensors have attracted intensive attention...
Electrocatalytic two‐electron oxygen reduction has emerged as a promising alternative to the energy‐ and waste‐intensive anthraquinone process for distributed H2O2 production. This process, however, suffers from strong competition from the four‐electron pathway leading to low H2O2 selectivity. Herein, we report using a superhydrophilic O2‐entrapping electrocatalyst to enable superb two‐electron oxygen reduction electrocatalysis. The honeycomb carbon nanofibers (HCNFs) are robust and capable of achieving a high H2O2 selectivity of 97.3 %, much higher than that of its solid carbon nanofiber counterpart. Impressively, this catalyst achieves an ultrahigh mass activity of up to 220 A g−1, surpassing all other catalysts for two‐electron oxygen reduction reaction. The superhydrophilic porous carbon skeleton with rich oxygenated functional groups facilitates efficient electron transfer and better wetting of the catalyst by the electrolyte, and the interconnected cavities allow for more effective entrapping of the gas bubbles. The catalytic mechanism is further revealed by in situ Raman analysis and density functional theory calculations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.