Influence of Synthesis Conditions for ZSM-5 on the Hydrothermal Stability of Cu-ZSM-5

Berggrund, Malin; Ingelsten, Hanna Härelind; Skoglundh, Magnus; Palmqvist, Anders

doi:10.1007/s10562-009-9890-5

Cited by 23 publications

(7 citation statements)

References 32 publications

(42 reference statements)

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“…Noble metal catalysts exhibit high catalytic activity at low temperature, but are limited in industrial applications because of their high cost and poisoning problems [4,5,6,7,8,9]. Molecular sieve catalysts show certain catalytic activity but they are hydrothermally unstable and susceptible to structure collapse [10]. Transition metal oxides are cheap and also have good catalytic activity and, thus, can be appropriate catalysts for the catalytic oxidation of NO.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation of NO over MnOx–CeO2 and MnOx–TiO2 Catalysts

et al. 2016

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A series of MnO x -CeO 2 and MnO x -TiO 2 catalysts were prepared by a homogeneous precipitation method and their catalytic activities for the NO oxidation in the absence or presence of SO 2 were evaluated. Results show that the optimal molar ratio of Mn/Ce and Mn/Ti are 0.7 and 0.5, respectively. The MnO x -CeO 2 catalyst exhibits higher catalytic activity and better resistance to SO 2 poisoning than the MnO x -TiO 2 catalyst. On the basis of Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and scanning transmission electron microscope with mapping (STEM-mapping) analyses, it is seen that the MnO x -CeO 2 catalyst possesses higher BET surface area and better dispersion of MnO x over the catalyst than MnO x -TiO 2 catalyst. X-ray photoelectron spectroscopy (XPS) measurements reveal that MnO x -CeO 2 catalyst provides the abundance of Mn 3+ and more surface adsorbed oxygen, and SO 2 might be preferentially adsorbed to the surface of CeO 2 to form sulfate species, which provides a protection of MnO x active sites from being poisoned. In contrast, MnO x active sites over the MnO x -TiO 2 catalyst are easily and quickly sulfated, leading to rapid deactivation of the catalyst for NO oxidation. Furthermore, temperature programmed desorption with NO and O 2 (NO + O 2 -TPD) and in situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS) characterizations results show that the MnO x -CeO 2 catalyst displays much stronger ability to adsorb NO x than the MnO x -TiO 2 catalyst, especially after SO 2 poisoning.

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Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation of NO over MnOx–CeO2 and MnOx–TiO2 Catalysts

et al. 2016

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“…Hydrocarbo n [5,6], urea or ammonia [7][8][9] are usually used as the reductants. It was reported that Cu-ZSM-5 [10] had shown the promising performance for NO abateme nt, but its hydrothermal stability is poor [11,12].…”

Section: Introductionmentioning

confidence: 99%

In situ synthesis of CuSAPO-34/cordierite and its selective catalytic reduction of nitrogen oxides in vehicle exhaust: The effect of HF

Wang

Liu

Feng

et al. 2013

Fuel

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“…Many studies have been carried out to improve the hydrothermal stability of ZSM5 catalysts. [28][29][30][31] Recently, chabazite (CHA)-structured small-pore zeolites including Cu-SSZ13 and Cu-SAPO34 have been drawing keen interest from automobile industry as a highly promising commercial catalyst for SCR reactions due to their excellent lowtemperature activity and robust hydrothermal stability. [32][33][34][35][36][37][38] Fickel et al 33 reported that Cu-SSZ13 catalyst exhibited much higher deNOx activity than that of Cu-ZSM5 catalyst after hydrothermal aging at 750°C, even though its fresh activity was comparable to that of Cu-ZSM5 catalyst.…”

Section: Introductionmentioning

confidence: 99%

Experimental and kinetic analysis of hydrothermal aging effects on ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst

Wang¹,

Im²

2018

Proceedings of the Institution of Mechanical Engineers, Part D:

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Ammonia/urea selective catalytic reduction is an efficient technology to control NOx emission from diesel engines. One of its critical challenges is the performance degradation of selective catalytic reduction catalysts due to the hydrothermal aging experienced in real-world operations during the lifetime. In this study, hydrothermal aging effects on the reduction of ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst were investigated under actual engine exhaust conditions. Ammonia adsorption site densities of the selective catalytic reduction catalysts aged at two different temperatures of 750°C and 850°C for 25 h with 10% H2O were experimentally measured and compared to that of fresh catalyst on a dynamometer test bench with a heavy-duty diesel engine. The test results revealed that hydrothermal aging significantly decreased the ammonia adsorption capacity of the current commercial Cu-zeolite selective catalytic reduction catalyst. Hydrothermal treatment at 750°C reduced the ammonia adsorption site to 62.5% level of that of fresh catalyst, while hydrothermal treatment at 850°C lowered the adsorption site to 37.0% level of that of fresh catalyst. Also, in this study, numerical simulation and kinetic analysis were carried out to quantify the impact of hydrothermal aging on the reduction of ammonia adsorption capacity by introducing an aging coefficient. The kinetic parameter calibrations based on actual diesel engine tests with a commercial monolith Cu-zeolite selective catalytic reduction catalyst provided a highly realistic kinetic parameter set of ammonia adsorption/desorption and enabled a mathematical description of hydrothermal aging effect.

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Influence of Synthesis Conditions for ZSM-5 on the Hydrothermal Stability of Cu-ZSM-5

Cited by 23 publications

References 32 publications

Catalytic Oxidation of NO over MnOx–CeO2 and MnOx–TiO2 Catalysts

Catalytic Oxidation of NO over MnOx–CeO2 and MnOx–TiO2 Catalysts

In situ synthesis of CuSAPO-34/cordierite and its selective catalytic reduction of nitrogen oxides in vehicle exhaust: The effect of HF

Experimental and kinetic analysis of hydrothermal aging effects on ammonia adsorption capacity over a commercial Cu-zeolite selective catalytic reduction catalyst

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