Nitric acid is widely applied in agriculture and industry. The present manufacturing process via a combination of the Haber–Bosch process and the Ostwald oxidation process is accompanied by massive energy consumption and greenhouse gas emissions. The direct electrocatalytic nitrogen oxidation reaction (NOR) to nitric acid is a promising alternative, especially when it is driven by renewable energy sources. The standardization of performance evaluation is the prerequisite for the design and synthesis of efficient electrocatalysts for NOR. In this context, this Minireview first discusses the history of the development of HNO3 manufacturing and the possible reaction mechanisms for electrocatalytic NOR. Then, a strict protocol for electrochemical NOR experiments is recommended. Finally, general research targets associated with techno‐economic analysis, challenges, and prospects for NOR are summarized for future studies.

Electrocatalytic nitrite reduction is of great significance for wastewater treatment and value-added chemicals synthesis. This review highlights the latest progress in electrochemical nitrite reduction to produce two types of products,...

Electrocatalytic nitrogen oxidation to nitrate is a promising alternative to the conventional nitrate synthesis industry, which is accompanied by huge energy consumption and greenhouse gas emission. However, breaking the NN triple bond (941 kJ·mol–1) in nitrogen is still challenging, and thus, the development of efficient electrocatalysts with established reaction pathways is highly required. Herein, a series of Ru-doped Pd materials are prepared, and the optimized Pd0.9Ru0.1 sample exhibits superior performance for electrocatalytic nitrogen oxidation into nitrate, greatly outperforming pure Pd and Ru samples. The 15N isotope-labeling studies and other characterizations results indicate that the produced nitrate originates from N2 electrooxidation. Electrochemical in situ Raman spectra reveal the formed Pd0.9Ru0.1O2 on the surface serves as the active species. Electrochemical in situ Fourier transform infrared spectroscopy and online differential electrochemical mass spectrometry experimentally unveil the reaction pathway of nitrogen electrooxidation on Pd0.9Ru0.1O2. The combined results of experiments and theoretical simulations reveal Ru doping not only promotes the formation of more active species but also changes the potential-limiting step with a lower energy barrier.

No abstract

Electrochemical conversion of abundant carbon- and nitrogen-containing small molecules into high-valued organonitrogen compounds is alluring to reducing current dependence on fossil energy. Here we report a single-cell electrochemical oxidation approach to transform methanol and ammonia into formamide under ambient conditions over Pt electrocatalyst that provides 74.26% selectivity from methanol to formamide and a Faradaic efficiency of 40.39% at 100 mA cm−2 current density, gaining an economic advantage over conventional manufacturing based on techno-economic analysis. A 46-h continuous test performed in the flow cell shows no performance decay. The combined results of in situ experiments and theoretical simulations unveil the C–N bond formation mechanism via nucleophilic attack of NH3 on an aldehyde-like intermediate derived from methanol electrooxidation. This work offers a way to synthesize formamide via C–N coupling and can be extended to substantially synthesize other value-added organonitrogen chemicals (e.g., acetamide, propenamide, formyl methylamine).