Washcoating of Different Zeolites on Cordierite Monoliths

Mitra, Brishti; Kunzru, Deepak

doi:10.1111/j.1551-2916.2007.02032.x

Cited by 80 publications

(80 citation statements)

References 27 publications

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“…[ 127 ] It can be defi ned as the total external surface area of the foam struts per unit bulk volume assuming a perfectly smooth strut surface. [ 126 ] In reality, the dip-coating BEA silica and cordierite monoliths [ 104 ] wash-coating Cu-MFI cordierite monolith [ 105 ] slurry wash-coating NH 4 -MFI cordierite honeycombs [ 106 ] wash-coating MFI alumina-mullite foam [ 103 ] wash-coating MFI alumina-mullite foam [ 107 ] wash-coating MOR, MFI, BEA, FAU cordierite honeycomb [ 108 ] ceramic foam struts have a rough surface and may possess an additional internal void volume due to the removed polymeric template. [ 125 , 126 ] Therefore, conventional gas physisorption measurements, e.g.…”

Section: Solid Foam Monoliths As Supports For Zeolite Catalystsmentioning

confidence: 99%

Zeolitic Materials with Hierarchical Porous Structures

et al. 2011

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During the past several years, different kinds of hierarchical structured zeolitic materials have been synthesized due to their highly attractive properties, such as superior mass/heat transfer characteristics, lower restriction of the diffusion of reactants in the mesopores, and low pressure drop. Our contribution provides general information regarding types and preparation methods of hierarchical zeolitic materials and their relative advantages and disadvantages. Thereafter, recent advances in the preparation and characterization of hierarchical zeolitic structures within the crystallites by post-synthetic treatment methods, such as dealumination or desilication; and structured devices by in situ and ex situ zeolite coatings on open-cellular ceramic foams as (non-reactive as well as reactive) supports are highlighted. Specific advantages of using hierarchical zeolitic catalysts/structures in selected catalytic reactions, such as benzene to phenol (BTOP) and methanol to olefins (MTO) are presented.

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Section: Solid Foam Monoliths As Supports For Zeolite Catalystsmentioning

confidence: 99%

Zeolitic Materials with Hierarchical Porous Structures

et al. 2011

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“…In the slurry method, the particle size of the powder used for washcoating is kept between 2 and 5 m, so that most of the coating deposits on the channel walls and the maximum washcoat loading is independent of the micropore volume of the monolith (Nijhuisa et al, 2001). The effect of process parameters on washcoat properties has been studied by several investigators (Blachou et al, 1992;Kolb et al, 1993;Agrafiotis et al, 1999;Agrafiotis and Tsetsekou, 2000a,b;Zamaro et al, 2005a,b;Kumar and Kunzru, 2007;Mitra and Kunzru, 2008). The influence of particle size, slurry concentration, pH, and viscosity on washcoat properties such as loading, adhesion, and reproducibility have been reported.…”

Section: Introductionmentioning

confidence: 96%

Effect of method of preparation on activity of Pd/Al₂O₃ monolith catalysts

Mogalicherla

Kunzru

2010

Can J Chem Eng

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monolithic catalyst of different washcoat thicknesses were prepared by two methods and tested for the activity of hydrogenation of˛-methyl styrene. These catalysts were prepared by two methods; either the palladium was impregnated on -alumina and this Pd/Al 2 O 3 powder was used to prepare the slurry for washcoating (Cat 1) or -alumina washcoating was followed by impregnation of palladium (Cat 2). The effect of slurry concentration, pH of the slurry, and addition of binders on the catalyst properties was investigated. The monolithic catalysts were characterised by determination of metal dispersion, surface area, scanning electron microscopy, and weight loss of washcoat during ultrasonication. Well-adhered washcoats were obtained with slurry prepared using milled -alumina, whereas the adhesion of the washcoat prepared using Pd/Al 2 O 3 powders was very poor. Addition of binders significantly improved the adhesion of the washcoats prepared from Pd/Al 2 O 3 . Metal dispersion for Cat 2 decreased with washcoat loading but did not change with loading for Cat 1. The activity tests were conducted at different washcoat loadings and the productivity of the monolithic catalyst prepared in both methods has been compared. Des catalyseurs monolithiques de Pd/Al2O3 et d'épaisseurs de couche lavis différentes ontété préparées par deux méthodes et testées en termes d'activité pour l'hydrogénation du˛-méthyl-styrène. Ces catalyseurs ontété préparés par deux méthodes : 1) du palladium aété enduit sur de la -alumine et cette poudre de Pd/Al2O3était utilisée pour préparer la boue de couche lavis (Cat 1) ou 2) la préparation de la couche lavis de y-alumineétait suivie d'un enduit de palladium (Cat 2). On aétudié l'effet de la concentration de la boue, de son pH et de l'ajout de liants sur les propriétés des catalyseurs. On a déterminé les caractéristiques des catalyseurs monolithiques par détermination de la dispersion métallique, de la surface, par une microscopieélectroniqueà balayage et par la perte de poids de la couche lavis durant l'ultrasonication. Des couches lavis de bonne adhésion ontété obtenues avec des boues préparées en utilisant de la -alumine moulue, tandis que l'adhésion des couches lavis préparées avec des poudres de Pd/Al2O3était très mauvaise. L'ajout de liants améliorait de façon significative l'adhésion des couches lavis préparées avec le Pd/Al2O3. La dispersion métallique du Cat 2 diminuait avec la charge de couche lavis mais pour le Cat 1, cette dispersion n'était pas modifiée avec la charge. Ces tests d'activité ontété effectués pour différentes charges de couche lavis et l'on a comparé la productivité des catalyseurs monolithiques produits par les deux méthodes.

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“…The particle size of zeolites, as well as slurry concentration, can also influence the adherence [142,145]. To improve the adherence of the washcoat, a binder, for example silica, can be added [146,147].…”

Section: Coating Zeolites Onto Monolithsmentioning

confidence: 99%

Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

2017

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Considerable research has been conducted on monolithic catalysts for various applications. Strategies toward coating monoliths are of equal interest and importance. In this paper, the preparation of monoliths and monolithic catalysts have been summarized. More specifically, a brief explanation for the manufacturing of ceramic and metallic monoliths has been provided. Also, different methods for coating γ-alumina, as a secondary support, are included. Techniques used to deposit metal-based species, zeolites and carbon onto monoliths are discussed. Furthermore, monoliths extruded with metal oxides, zeolites and carbon are described. The main foci are on the reasoning and understanding behind the preparation of monolithic catalysts. Ideas and concerns are also contributed to encourage better approaches when designing these catalysts. More importantly, the relevance of monolithic structures to reactions, such as the selective oxidation of alkanes, catalytic combustion for power generation and the preferential oxidation of carbon monoxide, has been described.

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Washcoating of Different Zeolites on Cordierite Monoliths

Cited by 80 publications

References 27 publications

Zeolitic Materials with Hierarchical Porous Structures

Zeolitic Materials with Hierarchical Porous Structures

Effect of method of preparation on activity of Pd/Al₂O₃ monolith catalysts

Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

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Washcoating of Different Zeolites on Cordierite Monoliths

Cited by 80 publications

References 27 publications

Zeolitic Materials with Hierarchical Porous Structures

Zeolitic Materials with Hierarchical Porous Structures

Effect of method of preparation on activity of Pd/Al2O3 monolith catalysts

Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

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Product

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Effect of method of preparation on activity of Pd/Al₂O₃ monolith catalysts