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Adsorption is a promising technology for deep purification of nitrogen oxides (NO x) from flue gases and simultaneously recycling NO 2 as an economically valuable chemical. Zeolite as a robust NO x adsorbent provides the key step for success in practical applications, of which the screening remains challenging regarding the NO-NO 2 …
@article{Gu2020IntegrationOA, title={Integration of an Oxidation Catalyst with Pd/Zeolite-Based Passive NOx Adsorbers: Impacts on Degradation Resistance and Desorption Characteristics}, author={Yu Gu and Silvia Marino and Marina Cort{'e}s-Reyes and Izabela S. Pieta and Josh A. Pihl and William S. Epling}, journal={Industrial & …
This is a follow-up report about the development of a cost-effective Palladium (Pd) zeolite-based (HC/NOx trap type) cold-start catalyst (CSC) [1] to meet the future more stringent Chinese vehicle tailpipe emission standard.The impacts of Pd /stabilizer combination within zeolite for the HC/NOx trapping efficiency, the high temperature …
Extruded Zeolite Based Honeycomb Catalyst for NOx Removal from Diesel Exhaust. 24. The most promising technique to reduce the NOx emissions from diesel engines is the SCR-technology. This technique is well known since several years and derived from the exhaust gas treatment of power plants and stationary engines.
Herein, a novel zeolite-like Ce-Si5Al2O x catalyst derived from an ultrasmall nanozeolite EMT precursor was synthesized without organic templates at ambient temperature. This catalyst was able to ...
Fe-zeolite and V-based catalysts were noticeably affected by the NO 2 /NOx ratio. ... engine installed with DOC and DPF was used to investigate the NO x reduction and the N 2 O emission properties of an iron based zeolite and a vanadium-based urea-SCR under various operating conditions. 2.
To meet the increasingly stringent nitrogen oxides (NOx) emission regulations of diesel engines, the selective catalytic reduction (SCR) of NOx with ammonia (NH 3) has become the current mainstream technical route.Experiments in the present study included the performance of Cu-Beta catalyst and Cu-CHA catalyst before and after hydrothermal …
Fully ion-exchanged Pd/SSZ-13 model passive NOx adsorbers (PNA) exhibit significant NOx storage capability, achieving NOx-to-Pd ratios of 1, and NOx desorption at higher temperatures, where downstream NOx reduction catalysts are active, under simulated exhaust conditions. However, CO has been found to induce PNA degradation, which …
The selective catalytic reduction (SCR) of NOx with NH3 at high temperature (T > 500 °C) usually has low conversion efficiency due to the undesired NH3 over-oxidation. To suppress the oxidation of NH3 to NOx, we proposed a Fe-exchanged zeolite catalyst with the modification of Ni and W for the NH3-SCR process, which was investigated in a …
Vanadium-based catalysts have been used for several decades in ammonia-based selective catalytic reduction (NH3-SCR) processes for reducing NOx emissions from various stationary sources (power plants, chemical plants, incinerators, steel mills, etc.) and mobile sources (large ships, automobiles, etc.). Vanadium-based …
DOI: 10.1016/j.jes.2023.10.012 Corpus ID: 264399320; Review of Core-shell structure zeolite-based catalysts for NOx emission control @article{Jia2023ReviewOC, title={Review of Core-shell structure zeolite-based catalysts for NOx emission control}, author={Lingfeng Jia and Jixing Liu and Huifang Cheng and Zhen Zhao and Jian Liu}, journal={Journal of …
The framework stability of zeolite-based catalysts was evaluated via Al 2p analysis (see Fig. 9 C), since the substitution of Al for Si creates a fundamental NH 3-SCR active site [31]. Two deconvoluted signals centered at 75.4 and 74.5 eV corresponding to the Al atom in the form of Al–OH and Al–O [32].
Zeolite-Based Hydrocarbon Traps and Passive NO. x. Adsorbers for Vehicle Cold Start Applications. Lee, Jungkuk. State University of New York at Buffalo ProQuest Dissertations Publishing, 2021. 28417752. Explore millions of resources from scholarly journals, books, newspapers, videos and more, on the ProQuest Platform.
In addition, the Cu-based zeolite and Ag/Al 2 O 3 catalysts applied in the HC-SCR reactions were also reviewed, which focused on the structure-activity relationship, reaction mechanisms, and the methods to ... Mechanism of the selective reduction of NOx by methane over Co-ZSM-5. Appl. Catal. B Environ., 230 (2018), pp. 184-193. View PDF …
The NO 2 /NOx ratio in zeolite-based SCR catalysts is known to have a major effect on their catalytic efficiency, with an optimum around the 0.5 value – an equimolar mixture of NO and NO 2 [11]. That is why a catalyst's ability to modify the NO 2 /NOx ratio in situ may have a substantial impact on its performance.
A steam-dealuminated, acid-washed Pt/Y zeolite with n Si /n Al =14 in the form of a monolith showed the best catalytic performance and high resistance to poisoning by water and sulfur dioxide: at a space velocity of 40 000 h −1 (based on the monolith volume corresponding to at least a 10 times higher space velocity on the basis of the ...
The copper based zeolite catalyst processed through direct synthesis method have an efficient hydrothermal stability, hence shows a better selective catalyst reduction [60]. ... NOx Conversion for Fe-Zeolite. With the increase of NH 3 concentration, the NOx reduction ability decreases to below 300 °C for Fe-Z. Conversely, it also applies …
4. Currently, to reduce NO x emissions and improve catalytic activity, as well as to extend practical applications, there are still challenges for zeolite-based SCR catalysts, such as control of Al distribution in the framework for enhancing catalytic performance, increasing hydrothermal stability, and reducing the cost.
Zeolite-based passive NOx adsorbents (PNA) have emerged recently, which require much more research for commercial applications. As a major source of air pollution, NOx …
Later, they found that H-FER zeolite is as effective as vanadium-based catalysts in CH 3 OH-SCR with good durability, hydrothermal stability and SO x resistance [18]. As shown in the Fig. 6 c, Si–O(H)–Al sites and neighboring EFAL species in H-FER were suggested to synergistically catalyze the formation of nitromethane as a key …
Numerous catalysts such as zeolites, noble metals and metal oxides have been studied for NOx HC-SCR. The limited use of zeolite-based catalysts is due to hydrothermal deactivation and high ...
In particular, Pd-based PNA could release NOx quickly with the temperature increasing due to the weak interaction between NOx and Pd species, ... Hence, it seems that the adsorption strength between NOx and the Pd/zeolite PNAs could be adjusted by controlling the particle size of zeolitic support.
Abstract. NO x, as the main air pollutant in the atmosphere, its elimination has attracted wide attention. Several technologies for eliminating NO x have been …
During the past decade renewed interest in zeolite-based lean NOx reduction was spurred by the discovery of the very high activity of Cu-SSZ-13 (and the isostructural Cu-SAPO-34) in the NH3-SCR of ...
Starting from this pioneering work, research on zeolite-based LTNAs has intensified in recent years [12] [13] [14][15][16][17]. Zheng et al. [13] compared Pd-doped ZSM-5 (Zeolite Socony Mobil-type ...
@article{osti_1765172, title = {Integration of an Oxidation Catalyst with Pd/Zeolite-Based Passive NOx Adsorbers: Impacts on Degradation Resistance and Desorption Characteristics}, author = {Gu, Yuntao and Marino, Silvia and Cortés-Reyes, Marina and Pieta, Izabela S. and Pihl, Josh A. and Epling, William S.}, abstractNote = …
Abstract. Cu-exchanged zeolites have demonstrated widespread use as catalyst materials in the abatement of NO x, …
The NOx reduction activity increased with the NH 3 /NOx ratio of 1.3 and above [22]. Copper with beta zeolite (Cu/BEA) has a relatively higher NO oxidation potential as compared to its chabazite counterparts [33] when investigated with a 1:1 ratio of NH 3:NO (400 ppm) at a GSHV of 30,300 h −1 with Ar as carrier gas. The catalyst was …
NOx conversion efficiency is a significant factor in choosing a catalyst. Various research is being conducted to improve this efficiency by finding a suitable catalyst. SCR catalysts can be broadly grouped into traditional-based and zeolite-based catalysts. 2.1. Traditional catalyst2.1.1. Vanadium
The desorption temperature of stored NOx was strongly affected by the zeolite framework. •. Small-pore zeolites with high hydroteal stability have superior advantages for passive NOx adsorbers. The use of a passive NOx adsorber (PNA) for NOx storage during the cold-start period is crucial for eliminating NOx emissions from the …
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