Selective catalytic reduction of NOX

A mathematical model for the design of extruded honeycomb reactor for selective catalytic reduction of NOx... 

Development of Catalytic Processes for the Selective Catalytic Reduction of NOx into N2... 

A wide range of catalytic materials have been investigated for the selective catalytic reduction of NOx. For stationary emissions, NH3-SCR using vanadium-tungsten oxides supported on titania is the most used method however, when there is a simultaneous emission of NO and NOz (in tail gas from nitric acid plants), copper-based zeolites or analogous systems have been proven to be preferable [31b], In fact, there are two main reactions for NH3-SCR ... 

Busca, G., Lietti, L., Ramis, G. et al. (1998) Chemical and mechanistic aspects of the selective catalytic reduction of NOx by ammonia over oxide catalysts A review, Appl. Catal. B Environ., 18, 1. 

Brosius, R., Bazin, P., Thibault-Starzyk, F. et al., (2005) Operando FTIR study of reaction pathways of selective catalytic reduction of NOx with decane in the presence of water on iron-exchanged MFI-type zeolite, J. Catal., 234, 191. 

Devadas, M., Krocher, O. and Wokaun, A. (2005) Catalytic Investigation of Fe-ZSM5 in the Selective Catalytic Reduction of NOx with NH3, React. Kin. Catal. Lett., 86, 347. 

Selective catalytic reduction of NOx by NH3 on V-Mo-zeolite prepared by solid-state ion exchange method... 

V-Mo-Zeolite catalysts prepared by solid-state ion exchange were studied in the selective catalytic reduction of NOx by ammonia. The catalysts were characterized by chemical analysis, X-ray powder diffraction, N2 adsorption (BET), DRIFT, UV-Vis and Raman, spectroscopy and H2 TPR. Catalytic results show that upon addition of Mo to V-ZSM-5, catalytic performance was enhanced compared to V-ZSM-5. 

Gaseous pollutants in combustion exhaust gases dry sorbent injection, semidry sorbent injection, wet sorbent injection, selective noncatalytic reduction of N()x (SNCR), selective catalytic reduction of NOx (SCR). 

The present chapter will primarily focus on oxidation reactions over supported vanadia catalysts because of the widespread applications of these interesting catalytic materials.5 6,22 24 Although this article is limited to well-defined supported vanadia catalysts, the supported vanadia catalysts are model catalyst systems that are also representative of other supported metal oxide catalysts employed in oxidation reactions (e.g., Mo, Cr, Re, etc.).25 26 The key chemical probe reaction to be employed in this chapter will be methanol oxidation to formaldehyde, but other oxidation reactions will also be discussed (methane oxidation to formaldehyde, propane oxidation to propylene, butane oxidation to maleic anhydride, CO oxidation to C02, S02 oxidation to S03 and the selective catalytic reduction of NOx with NH3 to N2 and H20). This chapter will combine the molecular structural and reactivity information of well-defined supported vanadia catalysts in order to develop the molecular structure-reactivity relationships for these oxidation catalysts. The molecular structure-reactivity relationships represent the molecular ingredients required for the molecular engineering of supported metal oxide catalysts. 

Ozone decomposition in airplanes Selective catalytic reduction of NOx Arrays of corrugated plates Arrays of fibers Gauzes Ag Methanol -> formaldehyde Pt/Rh NO production from ammonia HCN production from methane Foams Catalytic membranes reactors... 

The selective catalytic reduction of NOx with urea or ammonia... 

Iwamoto independently reported the selective catalytic reduction of NOx by... 

In-Sik Nam and Moon Hyeon Kim (Pohang University of Science and Technology, Korea) review new materials for the selective catalytic reduction of NOx from combustion processes. Despite significant research efforts over the last 20 years, there are still unresolved issues, such as inhibition and deactivation by steam. The authors show how new synthesis methods, especially for zeolites, can be used to improve these catalysts. 

L.A.H. Andersson, J.G.M. Brandin and C.U.I. Odenbrand, Selective catalytic reduction of NOx over acid-leached mordenite catalysts. Cat. Today 4 (1989) 173-185. 

In this section, the selective catalytic reduction of NOx with NH3 is emphasized. This reaction is the basis of the selective catalytic reduction (SCR) process that removes NOx from oxygen-rich emissions that occur in power plants, waste incinerators, and gas turbines. 

Bond and Flamerz Tahir [62] reviewed the literature on the preparation, structure and catalytic properties of vanadium oxide monolayer catalysts. This catalyst plays an essential role in the selective catalytic reduction of NOx-... 

Selective Catalytic Reduction of NOx by Hydrocarbons Over Ag/Al203... 

Eranen, K., Lindfors, L.-E., Niemi, A., Elfving, P. and Cider, L. (2000) Influence of hydrocarbons on the selective catalytic reduction of NOx over Ag/Al2Oj -laboratory and engine tests. SAE paper, 012813. 

Lindfors, L.-E., Eranen, K., Klingstedt, F. and Murzin, D.Yu. (2004) Silver/alumina catalyst for selective catalytic reduction of NOx to N2 by hydrocarbons in diesel powered vehicles. Top. Catal., 28, 185-189. 

He, H. and Yu, Y. (2005) Selective catalytic reduction of NOx over Ag/Al203 catalyst from reaction mechanism to diesel engine test. Catcd. Today, 100, 37-47. 

Zhang, X., He, H. and Ma, Z. (2007) Hydrogen promotes the selective catalytic reduction of NOx by ethanol over Ag/Al203 Catal. Commun., 8, 187-192. 

Breen, J.P. and Burch, R. (2006) A review of the effect of the addition of hydrogen in the selective catalytic reduction of NOx with hydrocarbons on silver catalysts. Top. Catal, 39, 53-58. 

Sazama, P. and Wichterlova, B. (2005) Selective catalytic reduction of NOx by hydrocarbons enhanced by hydrogen peroxide over silver/alumina catalysts. Chem. Commun, 38, 4810-4811. 

Partial oxidation of propane (Coating characterization) Partial oxidation of propane Selective catalytic reduction of NOx (Coating characterization) Water gas shift Methane steam reforming Methanol steam reforming Schwarz et al. [178] Roumanie et al. [179] Pennemann et al. [183] Ercoli et al. [184] Stefanescu et al. [181] Germani et al. [177] Tonkovich et al. [182] Yu et al. [185]... 

The nature and mobility of ions and solvent in zeolite cages will affect the ac-impedance of the material. This effect can be utilized for zeolite-based sensor concepts where a zeolite film is coated on interdigitated electrodes. For example, it was shown that the impedance of a film of proton-conducting H-ZSM-5 is influenced by the presence of ammonia (Figs. 15, 16).[126,127] The ammonia is protonated in the zeolite, thus producing much larger ammonium ions with different mobilities in the zeolite that can be detected by impedance spectroscopy. The detection of ammonia is of interest for automotive applications where the selective catalytic reduction of NOx by ammonia is envisioned. 

E. Vogt, A. van Dillen, J. Geus and F. Janssen, "Selective Catalytic Reduction of NOx with NH3 over a V205/TiO2 on Silica Catalyst", Catalysis Today. 1988,2.569-579. 

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