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Ammonia

About: Ammonia is a research topic. Over the lifetime, 16217 publications have been published within this topic receiving 271940 citations. The topic is also known as: NH3 & azane.


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Journal ArticleDOI
TL;DR: The compensation points in several species are near the low partial pressures found in unpolluted air and approximate to the K(m) of glutamine synthetase in vitro, and in P. vulgaris L., the compensation point increases with temperature, termed the ammonia compensation point.
Abstract: Whole shoots of Phaseolus vulgaris L. and other species were exposed to a range of partial pressures of gaseous ammonia in air and the resulting fluxes were measured. Net uptake is linear with partial pressure in the range 5 to 50 nanobars and is zero at a finite partial pressure, termed the ammonia compensation point. Below the compensation point, ammonia (or possibly other volatile amines) is evolved by the leaves. The compensation points in several species are near the low partial pressures found in unpolluted air and approximate to the Km of glutamine synthetase in vitro. In P. vulgaris L., the compensation point increases with temperature.

453 citations

Journal ArticleDOI
TL;DR: In this article, the use of ionic liquids that have high N2 solubility as electrolytes was used to achieve high conversion efficiency of 60% for N2 electro-reduction to ammonia on a nanostructured iron catalyst under ambient conditions.
Abstract: Ammonia as the source of most fertilizers has become one of the most important chemicals globally. It also is being increasingly considered as an easily transported carrier of hydrogen energy that can be generated from “stranded” renewable-energy resources. However, the traditional Haber–Bosch process for the production of ammonia from atmospheric nitrogen and fossil fuels is a high temperature and pressure process that is energy intensive, currently producing more than 1.6% of global CO2 emissions. An ambient temperature, electrochemical synthesis of ammonia is an attractive alternative approach, but has, to date, not been achieved at high efficiency. We report in this work the use of ionic liquids that have high N2 solubility as electrolytes to achieve high conversion efficiency of 60% for N2 electro-reduction to ammonia on a nanostructured iron catalyst under ambient conditions.

453 citations

Journal ArticleDOI
TL;DR: In this paper, surface-enhanced infrared absorption spectroscopy (SEIRAS) was employed to study the reaction mechanisms of nitrogen reduction on an Au thin film for the first time.
Abstract: The electrochemical reduction of nitrogen to ammonia on Au-based catalysts showed a reasonably high Coulombic efficiency. The pathway of this promising reaction, however, is not clear partially due to the lack of information on reaction intermediates. Herein, surface-enhanced infrared absorption spectroscopy (SEIRAS) was employed to study the reaction mechanisms of nitrogen reduction on an Au thin film for the first time. During the nitrogen reduction, the N2Hy species was detected with bands at 1453 (H-N-H bending), 1298 (-NH2 wagging), and 1109 cm-1 (N-N stretching) at potentials below 0 V against reversible hydrogen electrode. This result indicates that the nitrogen reduction reaction on Au surfaces follows an associative mechanism, and the N≡N bond in N2 tends to break simultaneously with the hydrogen addition. By comparison, no absorption band associated with N was observed on Pt surfaces under the same reaction condition. This result is consistent with the low efficiency of nitrogen reduction on Pt due to the much faster kinetics of hydrogen evolution reaction.

449 citations

Journal ArticleDOI
TL;DR: The Southern California Air Quality Study (SCAQS) was conducted at more than 40 locations to acquire a database with meteorological, air quality, and visibility measurements, and to assess the causes of elevated ozone and suspended particulate matter concentrations throughout metropolitan Los Angeles, CA (the South Coast Air Basin) as mentioned in this paper.

442 citations

Journal ArticleDOI
TL;DR: The results show that in most of the cases studied, the presence of organic compounds enhances the uptake of ammonium ion onto the ion exchangers, and ion exchange offers a number of advantages including the able to handle shock loadings and the ability to operate over a wider range of temperatures.

431 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,701
20223,035
2021425
2020443
2019496
2018511