Coupled uptake and conversion of C12H26 and NO on Pd/SSZ-13: Experiments and modeling

Ambast, Mugdha; Malamis, Sotirios A.; Harold, Michael P.

doi:10.1016/j.cej.2021.129958

Cited by 12 publications

(11 citation statements)

References 35 publications

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“…Recently, Pd-exchanged zeolites were proposed as promising materials for this technology. , Highly dispersed Pd ions at exchange sites of a zeolite have been suggested as active sites for NO x storage at low temperatures . Subsequently, many research groups have studied NO x adsorption/desorption properties over Pd zeolites. − Small-pore Pd-SSZ-13 with chabazite (CHA) topology showed advantageous NO x release temperatures and higher hydrothermal stability compared to medium- and large-pore Pd zeolites. , …”

Section: Introductionmentioning

confidence: 99%

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

et al. 2022

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Noble metal-exchanged small-pore molecular sieves with chabazite topology are promising materials for automotive cold-start NO x emission control applications. A combination of first-principles thermodynamics and density functional theory was applied for the prediction of monomeric palladium, platinum, and ruthenium species formed in 1Al or 2Al sites of six-/eight-membered rings of the SSZ-13 framework in the presence of SO 2 , NO, O 2 , and H 2 O at temperatures between 0 and 1100 K. Calculations using gradient-corrected Perdew−Burke−Ernzerhof (PBE) functional and hybrid Heyd−Scuseria−Ernzerhof (HSE06) functional showed that the binding energy of NO adsorbed on Pd, Pt, or Ru ions is a strong function of exchange−correlation functional. Use of the PBE functional overestimated the binding strengths of NO to Pd, Pt, or Ru ions compared to the HSE06 functional. While PBE led to the adsorption of two NO per Pd, Pt, or Ru ion, HSE06 predicted the adsorption of a single NO. Isolated Pd, Pt, or Ru ions in 1Al sites tended to bind NO stronger than their counterparts in 2Al sites. Both functionals revealed that Pd and Pt ions have more similarities in terms of both NO adsorption and sulfur resistance compared to Ru ions. The results of this study are beneficial for further modeling of passive NO x adsorbers with improved properties to deliver cleaner tailpipe emissions during engine cold start.

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Section: Introductionmentioning

confidence: 99%

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

et al. 2022

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“…FTIR results [49] further showed the transformation of Pd 2+ (NO) to Pd 2+ (NO) (C 2 H 4 ) complex after Pd/SSZ-13 that had adsorbed NO was exposed to C 2 H 4 , indicating NO and HCs co-adsorption The strong interaction between C 2 H 4 and Pd 2+ ions increased the NO storage content at a fixed uptake temperature (around 100 • C), which also shifted the NO x release to higher temperatures in Pd/SSZ-13 [33,36]. It was also reported that Pd/SSZ-13 exhibited different NO uptake/release features in the presence of NO + C 2 H 4 , C 10 H 12 , toluene, and C 12 H 26 respectively [33,36,39]. This clearly demonstrates that the types of HCs impact the chemistry occurring in co-adsorption/release of NO + HCs on Pd/SSZ-13.…”

Section: Introductionmentioning

confidence: 87%

“…Hydrocarbons, which are always present in vehicle exhaust, also impact the NO adsorption over Pd/SSZ-13 [33,[36][37][38][39][40]. In recent decades, it has been found that zeolites have the ability to store HCs at temperatures below 200 • C, while the presence of H 2 O was found to be detrimental for HC storage [7,41].…”

Section: Introductionmentioning

confidence: 99%

Mechanistic insight in the propylene derived distinct NO uptake and release behaviors on Pd/SSZ-13 for low-temperature NO adsorption

Zhao

Chen

Hill

et al. 2023

Chemical Engineering Journal

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“…117 On the contrary, long-chain HC molecules, such as C 12 H 26 , showed almost no effect on the NO adsorption but prohibited the low-temperature NO release, over Pd-SSZ-13 (Figure 10d). 118 However, Pd-SSZ-13 presaturated with C 12 H 26 suffered a partial loss of NO adsorption capacity. Based on nonbonding interaction between adsorbed molecules and zeolites, 119,120 it was inferred that C 12 H 26 , which was adsorbed on the zeolite sites through van der Waals interaction, would not compete with NO for the cationic Pd sites.…”

Section: Co Co-induced Deactivation Of Pd-zeolites Has Beenmentioning

confidence: 99%

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

Liu

Chen

et al. 2023

Environ. Sci. Technol.

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It remains a major challenge to abate efficiently the harmful nitrogen oxides (NO x ) in low-temperature diesel exhausts emitted during the cold-start period of engine operation. Passive NO x adsorbers (PNA), which could temporarily capture NO x at low temperatures (below 200 °C) and release the stored NO x at higher temperatures (normally 250–450 °C) to downstream selective catalytic reduction unit for complete abatement, hold promise to mitigate cold-start NO x emissions. In this review, recent advances in material design, mechanism understanding, and system integration are summarized for PNA based on palladium-exchanged zeolites. First, we discuss the choices of parent zeolite, Pd precursor, and synthetic method for the synthesis of Pd-zeolites with atomic Pd dispersions, and review the effect of hydrothermal aging on the properties and PNA performance of Pd-zeolites. Then, we show how different experimental and theoretical methodologies can be integrated to gain mechanistic insights into the nature of Pd active sites, the NO x storage/release chemistry, as well as the interactions between Pd and typical components/poisons in engine exhausts. This review also gathers several novel designs of PNA integration into modern exhaust after-treatment systems for practical application. At the end, we discuss the major challenges, as well as important implications, for the further development and real application of Pd-zeolite-based PNA in cold-start NO x mitigation.

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Coupled uptake and conversion of C12H26 and NO on Pd/SSZ-13: Experiments and modeling

Cited by 12 publications

References 35 publications

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

Mechanistic insight in the propylene derived distinct NO uptake and release behaviors on Pd/SSZ-13 for low-temperature NO adsorption

Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

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Coupled uptake and conversion of C12H26 and NO on Pd/SSZ-13: Experiments and modeling

Cited by 12 publications

References 35 publications

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

Computational Study of Noble Metal CHA Zeolites: NO Adsorption and Sulfur Resistance

Mechanistic insight in the propylene derived distinct NO uptake and release behaviors on Pd/SSZ-13 for low-temperature NO adsorption

Cold-Start NOx Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration

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Cold-Start NO_x Mitigation by Passive Adsorption Using Pd-Exchanged Zeolites: From Material Design to Mechanism Understanding and System Integration