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NOx
About: NOx is a research topic. Over the lifetime, 26367 publications have been published within this topic receiving 496555 citations.
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TL;DR: In this article, the effects of blending n-pentanol, a second generation biofuel with diesel on the performance and emission characteristics of a diesel engine under exhaust gas recirculation (EGR) conditions are investigated.
238 citations
TL;DR: In this paper, the authors present the first global model of atmospheric nitrate Δ17O and compare with available observations, showing that the model shows the best agreement with a global compilation of observations when assuming a Δ 17O value of tropospheric ozone equal to 35 and preferential oxidation of NOx by the terminal oxygen atoms of ozone.
Abstract: . The oxygen isotopic composition (Δ17O) of atmospheric nitrate is a function of the relative abundance of atmospheric oxidants (O3, ROx=OH+HO2+RO2) and the formation pathway of nitrate from its precursor NOx (=NO+NO2). Coupled observations and modeling of nitrate Δ17O can be used to quantify the relative importance of chemical formation pathways leading to nitrate formation and reduce uncertainties in the budget of reactive nitrogen chemistry in the atmosphere. We present the first global model of atmospheric nitrate Δ17O and compare with available observations. The largest uncertainty for calculations of nitrate Δ17O is the unconstrained variability in the Δ17O value of tropospheric ozone. The model shows the best agreement with a global compilation of observations when assuming a Δ17O value of tropospheric ozone equal to 35‰ and preferential oxidation of NOx by the terminal oxygen atoms of ozone. Calculated values of annual-mean nitrate Δ17O in the lowest model layer (0–200 m above the surface) vary from 7‰ in the tropics to 41‰ in the polar-regions. The global, annual-mean tropospheric inorganic nitrate burden is dominated by nitrate formation via NO2+OH (76%), followed by N2O5 hydrolysis (18%) and NO3+DMS/HC (4%). Calculated nitrate Δ17O is sensitive to the relative importance of each nitrate formation pathway, suggesting that observations of nitrate Δ17O can be used to quantify the importance of individual reactions (e.g. N2O5 hydrolysis) leading to nitrate formation if the Δ17O value of ozone is known.
238 citations
TL;DR: A series of Mn-Ce mixed oxide catalysts with different molar ratio of Mn/Ce were prepared by the surfactant-template (ST) method and conventional co-precipitation (CP) method for the selective catalytic reduction of NOx with ammonia (NH3-SCR) at low temperatures as mentioned in this paper.
236 citations
01 Jan 2009
TL;DR: In this article, the performance and emission characteristics of a compression ignition engine while using cerium oxide nanoparticles as additive in neat diesel and diesel-biodiesel-ethanol blends are analyzed.
Abstract: An experimental investigation is carried out to establish the performance and emission characteristics of a compression ignition engine while using cerium oxide nanoparticles as additive in neat diesel and diesel-biodiesel-ethanol blends. In the first phase of the experiments, stability of neat diesel and diesel-biodiesel-ethanol fuel blends with the addition of cerium oxide nanoparticles are analyzed. After series of experiments, it is found that the blends subjected to high speed blending followed by ultrasonic bath stabilization improves the stability. The phase separation between diesel and ethanol is prevented using vegetable methyl ester (Biodiesel) prepared from the castor oil through transesterification process. In the second phase, performance characteristics are studied using the stable fuel blends in a single cylinder four stroke computerised variable compression ratio engine coupled with an eddy current dynamometer and a data acquisition system. The cerium oxide acts as an oxygen donating catalyst and provides oxygen for the oxidation of CO or absorbs oxygen for the reduction of NOx. The activation energy of cerium oxide acts to burn off carbon deposits within the engine cylinder at the wall temperature and prevents the deposition of non-polar compounds on the cylinder wall results reduction in HC emissions. The tests revealed that cerium oxide nanoparticles can be used as additive in diesel and diesel-biodieselethanol blend to improve complete combustion of the fuel and reduce the exhaust emissions significantly.
236 citations
Patent•
24 Jul 1987
TL;DR: In this article, an NOx decomposition catalyst having a crystal structure shown in the specified crystalline structural formula in the passage of exhaust gas of an automobile equipped with an internal combustion engine is constituted for purifying exhaust gas.
Abstract: PURPOSE:To enable decomposition of NOx contained in large excess oxygen without using a conventional reducing agent by providing an NOx decomposition catalyst shown in the specified crystalline structural formula in the passage of exhaust gas of an automobile equipped with an internal combustion engine CONSTITUTION:An NOx decomposition catalyst having a crystal structure shown in the formula I (A shows alkaline earth metal such as Ba and Sr, B shows rare earth metal such as Y, Nd and La, C shows metal of copper group such as Cu and Ag, 0<=x<=30, 0<=y<=20, 0<=z<=40, 40<=alpha<=80, 0<=beta<=20) is formed A catalyst for purifying exhaust gas is constituted by providing this NOx decomposition catalyst 3 in the passage of exhaust gas of an automobile equipped with an internal combustion engine 1 By this catalyst constitution, NOx of ppm order contained even in large excess oxygen such as about 10% can be decomposed
236 citations