Grafting of Alumina on SBA-15: Effect of Surface Roughness

Zukal, Arnošt; Šiklová, Helena; Čejka, Jiřı́

doi:10.1021/la801547u

Cited by 94 publications

(66 citation statements)

References 29 publications

(48 reference statements)

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“…The Pd II -diamine complexes in more accessible locations will in turn have a greater chance to come off or decompose at higher temperatures. On the other hand, the organosilanes grafted in the second step may end up in the microporous or corrugated leftover porous structures that SBA-15 type materials typically have, [48,49] making them decompose rather slowly. The presence of the organoamine and palladium catalytic groups in the bifunctional catalysts was further corroborated by elemental analyses and ICP-AES, respectively (Table 2).…”

Section: [D] This Results Reflects Also the % Yield Of The P-iodo-β-nimentioning

confidence: 99%

Bifunctional Mesoporous Silica Catalyst for C–C Bond Forming Tandem Reactions

et al. 2011

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We report on the synthesis and catalytic properties of a class of hybrid organic-inorganic mesoporous bifunctional heterogeneous catalysts for efficient catalysis of two-step tandem reactions in one pot. With a solvent-assisted grafting method, two different catalytic groups, that is, an organoamine and a palladium-organodiamine complex, were immobilized onto high-surface-area mesoporous silica sequentially, by using their corresponding organosilanes in 2-propanol or toluene as the solvent in the first step and toluene as the solvent in the second step. Both MCM-41 and SBA-15 mesoporous silicas were used as support materials for the two catalytic groups, and the effect of different sequential grafting of the two organosilanes in 2-propanol or toluene on the structures and the catalytic properties of the resulting bifunctional catalysts were investigated. By using the resulting amine/Pd IIdiamine bifunctional mesoporous material as catalyst, the occurrence of two very important C-C bond forming reactions,

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Section: [D] This Results Reflects Also the % Yield Of The P-iodo-β-nimentioning

confidence: 99%

Bifunctional Mesoporous Silica Catalyst for C–C Bond Forming Tandem Reactions

et al. 2011

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“…It can be seen that normalized pore volume (NPV) decreased linearly with increasing V 2 O 5 loading. This implied that V 2 O 5 species are present inside the pores of the support [18].…”

Section: N 2 Adsorption Measurementmentioning

confidence: 99%

Active Sites Evaluation of Vanadia Based Powdered and Extruded SCR Catalysts Prepared on Commercial Titania

Murkute

VanderWiel

2015

Catal Lett

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The active sites of powder and monolith V 2 O 5 -WO 3 /TiO 2 catalysts prepared on commercial titania supports were studied for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) by ammonia (NH 3 ) while varying vanadium oxide (V 2 O 5 ) coverage. Four different types of commercial titania (DT-51, DT-56, G-5, and S-10) were used in this study. It was observed that the SCR activity of powder V 2 O 5 -WO 3 /TiO 2 is highly dependent on the vanadium coverage. The catalytic activity increased with increasing V 2 O 5 coverage and reached a maximum between one-half and one monolayer of vanadia. However, NO x conversion decreased at high V 2 O 5 coverage. The catalysts were characterized by temperature-programmed desorption of NH 3 (NH 3 TPD), temperature-programmed reduction by hydrogen (H 2 TPR), oxygen chemisorption, and N 2 adsorption to evaluate the active sites responsible for high SCR activity. The spectroscopic studies revealed that the rapid decrease in SCR activity at higher vanadia coverage is due to the decrease in the reducibility and dispersion of vanadium species. This synthetic learning was extended to investigate the active sites in extruded monolith V 2 O 5 -WO 3 /TiO 2 catalysts. A good correlation between redox sites and activity for powder and monolith V 2 O 5 -WO 3 /TiO 2 catalysts was found. Graphical Abstract 0.57 1.14

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“…4). It was reported that three distinct signals with maximum values centered at 3, 34 and 56 ppm should be assigned to octahedral Al (oct), pentahedral Al (pen) and tetrahedral Al (tet) atoms, respectively (Zukal et al 2008). …”

Section: Support and Catalyst Characterizationmentioning

confidence: 99%

“…Up to now, various pure silica mesoporous materials, such as MCM-41 (Goldbourt et al 2002;Landau et al 2001), SBA-15 (Zukal et al 2008;Baca et al 2008) and KIT-1 (Ryoo and Kim 1997;Jun and Ryoo 2000), have been employed as templates in many investigations concerning alumination of SiO 2 surfaces through grafting technology. Several researchers have investigated the HDS performance of catalysts supported on alumina-grafted materials.…”

Section: Introductionmentioning

confidence: 99%

The surface properties of aluminated meso–macroporous silica and its catalytic performance as hydrodesulfurization catalyst support

et al. 2017

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Aluminated mesoporous silica was prepared by multiple post-grafting of alumina onto uniform mesoporous SiO 2 , which was assembled from monodisperse SiO 2 microspheres. Hydrodesulfurization (HDS) catalyst was prepared by loading Ni and Mo active components onto the aluminated uniform mesoporous SiO 2 , and its HDS catalytic performance was evaluated using hydrodesulfurization of dibenzothiophene as the probe reaction at 300°C and 6.0 MPa in a tubular reactor. The samples were characterized by N 2 physisorption, scanning electronic microscopy, Fourier transform infrared spectrum, X-ray diffraction (XRD), temperature-programmed desorption of ammonia (NH 3 -TPD), 27 Al nuclear magnetic resonance ( 27 Al-NMR) and high-resolution transmission electron microscopy (HRTEM). The results showed that the Si-OH group content of SiO 2 was mainly dependent on the pretreatment conditions and had significant influence on the activity of the NiMo catalyst. The surface properties of the aluminated SiO 2 varied with the Al 2 O 3 -grafting cycles. Generally after four cycles of grafting, the aluminated SiO 2 behaved like amorphous alumina. In addition, plotting of activity of NiMo catalysts supported on aluminated mesomacroporous silica materials against the Al 2 O 3 -grafting cycle yields a volcano curve.

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Grafting of Alumina on SBA-15: Effect of Surface Roughness

Cited by 94 publications

References 29 publications

Bifunctional Mesoporous Silica Catalyst for C–C Bond Forming Tandem Reactions

Bifunctional Mesoporous Silica Catalyst for C–C Bond Forming Tandem Reactions

Active Sites Evaluation of Vanadia Based Powdered and Extruded SCR Catalysts Prepared on Commercial Titania

The surface properties of aluminated meso–macroporous silica and its catalytic performance as hydrodesulfurization catalyst support

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