Enhanced Electrocatalytic Conversion of Nitrates to Ammonia: Fuel from Waste

Abstract

Ammonia (NH3) is globally one of the most produced chemicals. Despite being known for its use as a fuel and as a precursor of multiple chemicals, during its production, it is responsible for more than 1.2% of the total global CO2 emission and consumes a large amount of energy. In this work, we studied a flow‐through membrane‐free electrocatalytic device (CMED) to produce continuous stream of NH3 from a common water contaminant, nitrate (NO3−). Indium‐palladium (In‐Pd) nanoparticles were impregnated in activated carbon cloth (ACC) and used as a cathode in the electrochemical device. It is found that in the counter electrode, adding oxygen evolution reaction (OER) active catalysts like platinum (Pt) for the regeneration of hydrogen ions enhances the rate of ammonia conversion to 7.28 µmol min−1 cm−2, eliminate the production of toxic nitrite by‐products, as well as provide a platform for a stable energy consumption over long periods of time. This method for the conversion of NO3− into NH3 promises a way forward for sustainable resource utilization while generating fuel from waste and contributing to future circular economies, and managing the nitrogen cycle in water that is a major challenge of the 21st century society.

CuCo2O4/CuO Heterostructure with Oxygen Vacancies Induced by Plasma for Electrocatalytic Nitrate Reduction to Ammonia

“…Ammonia (NH 3 ) is a crucial nitrogen-containing chemical widely used in various industries, primarily in the production of nitrogen-based fertilizers, plastics, refrigerants, and dyes. − It is also regarded as a green, clean energy source due to its mild combustion products and high energy density. Presently, the dominant industrial ammonia production method is the Haber-Bosch (H–B) process, which requires high temperatures (400–500 °C) and high pressures (150–300 atm) − and leads to massive fossil energy consumption and carbon dioxide emissions. , Given the dwindling reserves of fossil fuels and the escalating environmental concerns, it is urgent to develop an innovative alternative technology to displace the conventional H–B process for ammonia synthesis .…”