Advances in ammonia electrosynthesis from ambient nitrate/nitrite reduction

Multi-layer core–shell metal oxide/nitride/carbon and its high-rate electroreduction of nitrate to ammonia

“…Ammonia (NH 3 ) is an irreplaceable chemical raw material in human's manufacture and life, as the source material for nitrogen fertilizers, plastics, pharmaceuticals, explosives, synthetic fibers, resins and printing and dyeing. 1,2 According to statistics, the annual growth rate of ammonia production is expected to reach 40% by 2050 (>200 million tons). At present, the main technique adopted for ammonia production is the Haber-Bosch process (350-550 °C, 15-25 MPa), which has been recognized as an energy-intensive synthetic approach (consuming about 5.50 EJ per year) with a high carbon emission (450 million tons per year of CO 2 ).…”

High-Performance Electrocatalytic Reduction of Nitrite to Ammonia under Ambient Conditions on a FeP@TiO2 Nanoribbon Array

“…Ammonia (NH 3 ) plays a critical role as a fundamental chemical raw material and a carbon-free energy carrier, finding extensive applications in cosmetics, agricultural fertilizer production, and the food industry. − Until now, the large-scale industrial production of NH 3 has continued to rely on the Haber–Bosch process. This method utilizes hydrogen (H 2 ) and nitrogen (N 2 ) as raw materials and is conducted at high temperatures and pressures, leading to significant energy consumption and air pollution .…”

Cobalt-Nanoparticles-Decorated 3D Porous Nitrogen-Doped Carbon Network for Electrocatalytic Nitrite Reduction to Ammonia

“…Ammonia (NH 3 ) is an essential chemical raw material widely applied in the chemical industry, agriculture, pharmaceuticals, etc., and holds great potential as a clean energy carrier with high energy density (4.32 kW h kg –1 ). − Currently, the conventional industrial-scale NH 3 synthesis relies on the energy-intensive Haber–Bosch process, which accounts for approximately 1% of global energy consumption and generates ∼2% of carbon dioxide emissions annually, leading to significant energy and environmental challenges . The electrocatalytic nitrogen (N 2 ) reduction reaction (NRR) has emerged as a promising, pollution-free, and sustainable strategy for NH 3 generation. − Despite its potential, NRR faces challenges like low Faradaic efficiency (FE) and NH 3 yield due to the strong NN bond (941.0 kJ mol –1 ), ultralow water solubility of N 2 , and competition from the hydrogen evolution reaction.…”

“…Nitrite (NO 2 – ), as an alternative to N 2 , exhibits higher water solubility and smaller NO bond energy (204 kJ mol –1 ), which provides appealing conditions for enhancing NH 3 generation kinetics. − Beyond this, excessive NO 2 – released by industrial and agricultural activities could lead to severe environmental problems and endanger human health. , Electrocatalytic NO 2 – reduction is thus attractive for NH 3 synthesis while addressing the NO 2 – threat. Nevertheless, electrocatalytic NO 2 – reduction reaction (NO 2 – RR) involves a complex six-electron process that often generates undesired byproducts, thereby limiting NH 3 selectivity and yield. , Thus, exploring highly active and selective electrocatalysts for NH 3 synthesis via NO 2 – RR is of great value.…”

“…Nevertheless, electrocatalytic NO 2 − reduction reaction (NO 2 − RR) involves a complex six-electron process that often generates undesired byproducts, thereby limiting NH 3 selectivity and yield. 4,16 Thus, exploring highly active and selective electrocatalysts for NH 3 synthesis via NO 2 − RR is of great value.…”