Nitrogen oxides , reduction

This review has highlighted the key contributions of modern surface science to the understanding of the kinetics and mechanism of nitrogen oxide reduction catalysis. As discussed above, the conversion of NO has been taken as the standard to represent other NOx, and CO has typically been used as the reducing agent in these studies. The bulk of the work has been carried out on rhodium and palladium surfaces, the most common transition metals used in three-way catalytic converters. 

Miller, C. A., Lemieux, P. M. Touati, A. 1998. Evaluation of tire-derived fuel for use in nitrogen oxide reduction by rebuming. Journal of the Air and Waste Management Association, 48, 729-735. 

Payne, W. J., Grant, M. A., Shapleigh, J., and Hoffman, P. (1982). Nitrogen oxide reduction in Wolinella succinogenes and Campylobacter species. J. Bacterial. 152, 915-918. 

This chapter focuses on the chemistry ofbiomimetic copper nitrosyl complexes relevant to the NO-copper interactions in proteins that are central players in dissimilatory nitrogen oxide reduction (denitrification). The current state of knowledge of NO-copper interactions in nitrite reductase, a key denitrifying enzyme, is briefly surveyed the syntheses, structures, and reactivity of copper nitrosyl model complexes prepared to date are presented and the insight these model studies provide into the mechanisms of denitrification and the structures of other copper protein nitrosyl intermediates are discussed. Emphasis is placed on analysis of the geometric features, electronic structures, and biomimetic reactivity with NO or NOf of the only structurally characterized copper nitrosyls, a dicopper(II) complex bridged by NO and a mononuclear tris(pyrazolyl)hydroborate complex having a Cu(I)-NO formulation. 

Pathways and Controls of Nitrogen Oxide Reduction and Denitrification... 

Nitrogen oxides reductions through process changes and/or pollution prevention activities... 

Environmental benefits (e.g. carbon dioxide, nitrogen oxides reduction)... 

The state of the art of nitrogen oxides reduction over both massive and supported mixed oxides may be summarized as follows ... 

This paper reports first results of research and development work to achieve nitrogen oxide reduction under lean diesel exhaust gas conditions. Much attention is paid to the influence of operation conditions on catalyst performance. A major part of the paper deals with the influence of the hydrocarbon component, the hydrocarbon concentration and the HC/NO ratio on the activity of a special developed platinum based catalyst. Other aspects discussed are a spectroscopic characterization and a selectivity study. A hypothesis of a "dual-site" reaction mechanism for NOx-reduction in lean diesel exhaust gas precious metal based catalyst is established. Finally, first promising results on the performance of the catalyst system in a vehicle dynamometer test are given. 

Strontium cerates or strontium zirconates proton conductor can be used as the electrolyte membrane, with the results of nitrogen oxide reduction summarized in Table 8.8. When Pt/Ba/AljOs or EVSr/AljOs is used as working electrodes, it is possible to reduce the NO even in the presence of excess O2 (Kobayashi et a/., 2000,2002).The reduction of NO proceeds through the electrochemical reduction of NO absorbed into Sr/AljOa but not through the chemical reduction of NO by H2 gas. 

Like all other operators of combustion equipment, carbon black plants are subject to the usual pressures for reduced sulfur and nitrogen oxide emissions. It appears that the use of lower sulfur feedstock is the most economic way of reducing sulfur emissions. Redesign of combustion equipment for nitrogen oxide reduction is showing some promise. The primary NOx issues arise from the combustion of tail gas since the carbon black production process is exceedingly fuel-rich. 

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