Sulfur-tolerant BaO/ZrO2/TiO2/Al2O3 quaternary mixed oxides for deNOX catalysis

Say, Zafer; Mihai, Oana; Tohumeken, Merve; Ercan, Kerem Emre; Olsson, Louise; Özensoy, Emrah

doi:10.1039/c6cy01898j

Cited by 10 publications

(8 citation statements)

References 49 publications

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“…It seems that a high acidity of the support is required for a better S resistance. This was confirmed with AZT (Al2O3/ZrO2/TiO2) mixed oxides used as support of Pt/BaO 170 . The superior resistance to sulphur is correlated with an increase of the Lewis acidity.…”

Section: Improvement Of Sulphur Resistancesupporting

confidence: 56%

Chapter 3. NSR Catalytic Materials

Can¹,

Courtois²,

Duprez³

2018

Catalysis Series

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Imagined in the 90's, the NOx-storage and reduction (NSR) process operates with alternative cycles of long lean phases (NOx storage) and short rich phases (NOx reduction). NSR catalysts should possess at least two components: a basic oxide for trapping the NOx and a metallic component for the NO oxidation and the reduction of stored NOx. The reference material is composed of barium oxide (10-20 wt-%) deposited on a Pt/Al2O3 (1-2 % Pt). Improvements of NSR catalysts were obtained by changing (i) the basic component (especially potassium but it can also damage the catalyst substrate; other alkaline or alkaline-earth oxides were also envisaged); (ii) the support (especially cerium-based supports, or titania, hydrotalcites, perovskites); (iii) the metal (Rh is often added to improve the NOx reduction, and combinations of precious metals are considered). Noble metal-free catalysts were also developed, mainly based on cobalt, copper or manganese oxides. Perovskites including these transition metal oxides and potassium are also interesting for NSR applications. However, complete replacement of noble metal catalysts cannot be feasible yet. Usual NSR catalysts are sensitive to aging (sintering; strong of Ba-support interactions) and to sulphur poisoning but supports like TiO2 or cerium-based oxides can protect the catalyst from stable sulphate adsorption.

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Section: Improvement Of Sulphur Resistancesupporting

confidence: 56%

Chapter 3. NSR Catalytic Materials

Can¹,

Courtois²,

Duprez³

2018

Catalysis Series

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“…These trends pointed out possible roles of AZT in converting C s species via Reactions 10-12 (Table 1) and promoting Reaction 3. As explained in detail in one of our former reports [66], AZT is a complex mixed oxide. It lacks a well-defined XRD pattern, exhibits a quite disordered surface structure, and hosts a large number of various crystal defects such as oxygen vacancies, heterojunctions and interfacial sites, between various oxide domains.…”

Section: Effect Of Co 2 /G Ratiomentioning

confidence: 77%

Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas

Bac

Say

Koçak

et al. 2019

Applied Catalysis B: Environmental

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“…On the other hand, while QDs seem to increase NO conversion to a certain extent, the more noteworthy function of TGA-capped CdTe QDs is probably the photocatalytic conversion and storage of photogenerated NO 2 species into other oxidized surface species, such as HONO, HONO 2 , NO 2 – , NO 3 – , and −S–R–NO x (i.e., NO x bound to TGA). It is well known that NO(g) + O 2 (g) mixtures as well as NO 2 (g) can readily adsorb on numerous metal oxide surfaces in the form of nitrates, nitrites, as well as their protonated acidic forms. − NO x adsorption and successive oxidation and storage in the form of nitrates also serve as the basis of the nonphotocatalytic technology called NO x storage reduction, which is also called lean NO x traps that is commonly used in tail-pipe emission control systems of automobiles. As will be demonstrated below via further control experiments with TGA(aq)/TiO 2 , NO 2 capture cannot be solely achieved by the TGA capping (without CdTe QDs) through a simple adsorption process, but rather involves a photocatalytic action triggered by the entire TGA-CdTe QD system.…”

Section: Resultsmentioning

confidence: 99%

CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO₂ Storage Selectivity under UV and Vis Irradiation

Leinen

Dede

Khan

et al. 2018

ACS Appl. Mater. Interfaces

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Composite systems of P25 (titania) functionalized with thioglycolic acid (TGA)-capped CdTe colloidal quantum dots (QDs) were synthesized, structurally characterized, and photocatalytically tested in the photocatalytic NO x oxidation and storage during NO(g) + O 2 (g) reaction. Pure P25 yielded moderate-to-high NO conversion (31% in UV-A and 40% in visible (vis)) but exhibited extremely poor selectivity toward NO x storage in solid state (25% in UV-A and 35% in vis). Therefore, P25 could efficiently photooxidize NO(g) + O 2 (g) into NO 2 ; however, it failed to store photogenerated NO 2 and released toxic NO 2 (g) to the atmosphere. CdTe QD-functionalized P25 revealed a major boost in photocatalytic performance with respect to pure P25, where NO conversion reached 42% under UV-A and 43% under vis illumination, while the respective selectivity climbed up to 92 and 97%, rendering the CdTe/P25 composite system an efficient broad-band photocatalyst, which can harvest both UV-A and vis light efficiently and display a strong NO x abatement effect. Control experiments suggested that photocatalytic active sites responsible for the NO(g) + O 2 (g) photooxidation and formation of NO 2 reside mostly on titania, while the main functions of the TGA capping agent and the CdTe QDs are associated with the photocatalytic conversion of the generated NO 2 to the adsorbed NO x species, significantly boosting the selectivity toward solid-state NO x storage. Reuse experiments showed that photocatalytic performance of the CdTe/P25 system can be preserved to a reasonable extent with only a moderate decrease in the photocatalytic performance. Although some decrease in the photocatalytic activity was observed after aging, CdTe/P25 could still outperform P25 benchmark photocatalyst. Increasing CdTe QDs loading from the currently optimized minuscule concentrations could be a useful strategy to increase further the catalytic lifetime/stability of the CdTe/P25 system with only a minor penalty in catalytic activity.

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Sulfur-tolerant BaO/ZrO₂/TiO₂/Al₂O₃ quaternary mixed oxides for deNO_X catalysis

Abstract: A novel AZT – supported NSR/LNT catalyst with enhanced sulfur regeneration performance.

Cited by 10 publications

References 49 publications

Chapter 3. NSR Catalytic Materials

Chapter 3. NSR Catalytic Materials

Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas

CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO₂ Storage Selectivity under UV and Vis Irradiation

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Sulfur-tolerant BaO/ZrO2/TiO2/Al2O3 quaternary mixed oxides for deNOX catalysis

Abstract: A novel AZT – supported NSR/LNT catalyst with enhanced sulfur regeneration performance.

Cited by 10 publications

References 49 publications

Chapter 3. NSR Catalytic Materials

Chapter 3. NSR Catalytic Materials

Exceptionally active and stable catalysts for CO2 reforming of glycerol to syngas

CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO2 Storage Selectivity under UV and Vis Irradiation

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Sulfur-tolerant BaO/ZrO₂/TiO₂/Al₂O₃ quaternary mixed oxides for deNO_X catalysis

CdTe Quantum Dot-Functionalized P25 Titania Composite with Enhanced Photocatalytic NO₂ Storage Selectivity under UV and Vis Irradiation