High hydrothermal stability of Cu–SAPO-34 catalysts for the NH3-SCR of NOx

Niu, Chaoqun; Shi, Xun; Liu, Fudong; Li, Kuo; Xie, Lijuan; You, Yan

doi:10.1016/j.cej.2016.02.086

Cited by 123 publications

(50 citation statements)

References 47 publications

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“…Vanadia-based catalysts then became common and later on, metal-exchanged zeolites [1,[4][5][6]. Most recently, small-pore materials such as the zeolite Cu/SSZ-13 and the silicoaluminophosphate Cu/SAPO-34, have become popular subjects of research [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

et al. 2017

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Abstract:We developed a procedure for aqueous ion exchange to obtain different Cu loadings of Cu/SAPO-34 (between 0 and 2.6 wt %). The catalysts were washcoated on monoliths and characterised with respect to their activity and selectivity under standard selective catalytic reduction (SCR), fast SCR, NH 3 oxidation and NO oxidation reactions. They were further characterised using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), H 2 -temperature programmed reduction (H 2 -TPR), ultraviolet (UV)-vis spectroscopy and NH 3 adsorption. As expected, activity of all reactions increased with copper loading, due to increased number of active sites. However, the N 2 O formation during standard and fast SCR yielded interesting mechanistic information. We observed that N 2 O formation at low temperature increased with copper loading for the standard SCR reaction, while it decreased for fast SCR. The low-temperature N 2 O formation during fast SCR thus occurs predominantly over Brønsted sites. Species responsible for N 2 O formation during standard SCR, on the other hand, are formed on the copper sites. We further found that the fast SCR reaction occurs to a significant extent even over the H/SAPO-34 form. The Brønsted sites in SAPO-34 are thus active for the fast SCR reaction.

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Section: Introductionmentioning

confidence: 99%

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

et al. 2017

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“…As shown in Figure , Cu‐SAPO‐34 had the characteristic zeolite CHA diffraction peaks. The occurrence of higher peak intensities was used as an indication of a higher degree of crystallinity1 . With the presence of the binder, the characteristic diffraction peaks of the α‐alumina and γ‐alumina binders exist while the CHA diffraction peaks remain.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, Cu‐SAPO‐34 (Chabazite structured) catalysts with very high hydrothermal stability and activity for the NH 3 ‐SCR under oxidizing conditions were reported in . Beale et al renewed interest in zeolite‐based lean NO x reduction, spurred by the discovery of the very high activity of Cu‐SSZ‐13 (and that of isostructural Cu‐SAPO‐34) for the NH 3 ‐SCR of NO x .…”

Section: Introductionmentioning

confidence: 99%

Influence of alumina binders on adhesion and cohesion during preparation of Cu‐SAPO‐34/monolith catalysts

Kong

Qiu

Wang

et al. 2018

Int J Applied Ceramic Tech

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The adhesion and cohesion between the coating layers and the ceramic honeycombs are usually one of the key issues in the preparation of high‐performance zeolite‐based/Monolith catalysts. In this work, we investigate the deposition of high‐efficiency Cu‐SAPO‐34 catalyst on a cordierite monolith with special focus on the impact of alumina binders on the structure, mechanical adhesion and cohesion, and catalytic performance of the monolithic catalyst. Two kinds of alumina nanoparticles, α‐alumina and γ‐alumina, have no significant impacts on the Cu‐SAPO‐34 crystal structure, micropore morphology and catalytic activity. But washcoating experiments showed that the mass loss rate of the coating was less and the loading of the catalyst was higher when α‐alumina was used as the binder. The reason of improving the adhesion and cohesion strength is the suitable thermal shrinkage, the uniform distribution and densification structure of α‐alumina. Furthermore, optimization of the coating formulation with α‐alumina as the binder has been performed. Finally, the catalyst prepared under the optimal conditions was tested by SCR and a maximum conversion rate of 97.4% was obtained. It was concluded that the use of the washcoating method with α‐alumina does not affect catalytic performance while it increases bonding strength between substrate and catalysts.

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“…found that Cu‐SAPO‐34 possesses much higher hydrothermal stability compared with Cu‐SSZ‐13 after treating at 800 °C for 16 h (Figure a) . High hydrothermal stability was also observed for Cu‐SAPO‐34 synthesized using one‐pot method . Subsequently, Fe‐SAPO‐34 was integrated with commercial Cu‐CHA to achieve an excellent activity over an extended active temperature window owing to its superior activity and stability at high temperature (Figure b) .…”

Section: Current Zeolite‐based Nh3‐scr Materialsmentioning

confidence: 99%

Zeolitic Materials for DeNO_x Selective Catalytic Reduction

2017

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Selective catalytic reduction (SCR) of NOx has been proven to be the most efficient technique for the removal of NOx (deNOx) from flue gas of stationary sources and diesel engine exhaust of mobile sources. Among various SCR catalysts, zeolites are considered as the most promising candidates for heavy‐duty trucks owing to their benign nature, very high NOx conversion and N2 selectivity, as well as excellent hydrothermal stability at high temperatures. In recent years, a tremendous number of research articles have reported on the evolution of zeolitic materials for deNOx, which makes a critical review timely to provide inspiration for future development. This paper first gives a chronological progress of zeolite catalysts specifically highlighting the CHA zeolites, the hotspot of present research and application, followed by a summary on the synthesis of CHA zeolites, the structure–activity relationships, as well as the reaction mechanisms and kinetics. Last but not least, a critical outlook is given together with expected research directions in developing zeolite‐based catalysts for deNOx.

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High hydrothermal stability of Cu–SAPO-34 catalysts for the NH3-SCR of NOx

Cited by 123 publications

References 47 publications

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

Influence of alumina binders on adhesion and cohesion during preparation of Cu‐SAPO‐34/monolith catalysts

Zeolitic Materials for DeNO_x Selective Catalytic Reduction

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High hydrothermal stability of Cu–SAPO-34 catalysts for the NH3-SCR of NOx

Cited by 123 publications

References 47 publications

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

Influence of alumina binders on adhesion and cohesion during preparation of Cu‐SAPO‐34/monolith catalysts

Zeolitic Materials for DeNOx Selective Catalytic Reduction

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About

Zeolitic Materials for DeNO_x Selective Catalytic Reduction