Isopropylation of benzene over sulfated ZrO2–TiO2 mixed-oxide catalyst

Das, Debajyoti; Mishra, H.K.; Dalai, Ajay K.; Parida, Kulamani

doi:10.1016/s0926-860x(02)00550-1

Cited by 48 publications

(23 citation statements)

References 33 publications

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“…We also observed that calcination temperature has a direct effect on acidic properties of catalysts since the acidity of sample TZ-2(400) is 0.034 mmolg -1 which falls down to 0.018 mmolg -1 for sample TZ-2(600). Moreover from these results we can speculate the absence of Bronsted sites, since it has been reported that Bronsted sites corresponds to desorption temperatures higher than 400°C [39,40]. The nature of acid sites is very important property of these catalysts.…”

Section: Tpd Analysismentioning

confidence: 50%

TiO2-ZrO2 Binary Oxides for Effective Hydrodesulfurization Catalysts

Tiwari¹

2012

TOCATJ

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Titania-zirconia mixed oxide was developed as support for Mo, CoMo and NiMo catalysts. Synthesis was carried out using evaporation induced self assembly and modified sol-gel templating route. The samples were calcined in a temperature range of 400 o C to 600 o C. SEM and porosity analyses were used to ensure that the mesostructure is stable after Mo and promoter incorporation. Wide-angle XRD was used to verify MoO 3 (and MoS 2 ) dispersion, which indicated crystallite size <40Å up to 8wt% Mo loading. The IR spectral studies were used to determine the nature of Mo species (octahedral and tetrahedral). TPD study was used to determine the acidity of the supports. The physico-chemical properties were correlated with the catalytic hydrodesulfurization reaction. CoMo and NiMo catalysts were compared in order to gain an insight into the promoter effect on direct desulfurization pathways. A comparison with -Al 2 O 3 , SBA-15 and KIT-6 supported catalysts shows much superior activities of mesoporous titania-zirconia supported catalysts which is attributed to favorable metal-support interactions in case of mesoporous titania-zirconia supported catalysts.

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Section: Tpd Analysismentioning

confidence: 50%

TiO2-ZrO2 Binary Oxides for Effective Hydrodesulfurization Catalysts

Tiwari¹

2012

TOCATJ

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“…These solids have been used in several applications. [77][78][79][80] As-synthesized TiO 2 -ZrO 2 mixed oxides were investigated for their performance in the elimination of VOCs. Three supports were prepared with varying TiO 2 /ZrO 2 ratios: 20, 50 and 80 % Ti (T 20 Z 80 , T 50 Z 50 , and T 80 Z 20 respectively).…”

Section: Macro-mesoporous-mixed Tio 2 -Zromentioning

confidence: 99%

Noble‐Metal‐Based Catalysts Supported on Zeolites and Macro‐Mesoporous Metal Oxide Supports for the Total Oxidation of Volatile Organic Compounds

et al. 2011

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The use of porous materials to eliminate volatile organic compounds (VOCs) has proven very effective towards achieving sustainability and environmental protection goals. The activity of zeolites and macro-mesoporous metal-oxide supports in the total oxidation of VOCs has been investigated, with and without noble-metal deposition, to develop highly active catalyst systems where the formation of by-products was minimal. The first catalysts employed were zeolites, which offered a good activity in the oxidation of VOCs, but were rapidly deactivated by coke deposition. The effects of the acido-basicity and ionic exchange of these zeolites showed that a higher basicity was related to exchanged ions with lower electronegativities, resulting in better catalytic performances in the elimination of VOCs. Following on from this work, noble metals were deposited onto macro-mesoporous metal-oxide supports to form mono and bimetallic catalysts. These were then tested in the oxidation of toluene to study their catalytic performance and their deactivation process. PdAu/TiO(2) and PdAu/TiO(2) -ZrO(2) 80/20 catalysts demonstrated the best activity and life span in the oxidation of toluene and propene and offered the lowest temperatures for a 50 % conversion of VOCs and the lowest coke content after catalytic testing. Different characterization techniques were employed to explain the changes occurring in catalyst structure during the oxidation of toluene and propene.

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“…These Lewis acid sites increased the Bronsted acid strength of the surface hydroxyl groups present on the surfaces. Moreover, the chemical state of the sulfate groups sometimes determined the acidity of the oxide surfaces [37].…”

Section: Nh 3 -Temperature Programmed Desorptionmentioning

confidence: 99%

Preparation of Zirconia Promoted Sulfated Titania System with High Catalytic Activity

Yang³

et al. 2010

Chem Eng & Technol

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SO 42-/TiO 2 -ZrO 2 (STZ) solid superacid catalysts were prepared using the coprecipitation-impregnation method and characterized by FT-IR, XRD, NH 3 -TPD, N 2 adsorption-desorption isotherms, and SEM. It was observed that the sulfur content and the specific surface area of STZ changes with the ZrO 2 content, and passes through a maximum at Zr/Ti = 1/4. The results indicate that the molar ratio of Zr/Ti and nonionic surfactant, PEG, were helpful for increasing the surface areas and stabilizing the sulfate species on the surfaces of the catalysts. The catalytic activity results were supported by the hydrolysis reaction rate of 2-methyl-1,3-dioxane (2MD) that was strongly dependent on the sulfur content in the zirconia promoted sulfated titania catalyst.

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Isopropylation of benzene over sulfated ZrO2–TiO2 mixed-oxide catalyst

Cited by 48 publications

References 33 publications

TiO2-ZrO2 Binary Oxides for Effective Hydrodesulfurization Catalysts

TiO2-ZrO2 Binary Oxides for Effective Hydrodesulfurization Catalysts

Noble‐Metal‐Based Catalysts Supported on Zeolites and Macro‐Mesoporous Metal Oxide Supports for the Total Oxidation of Volatile Organic Compounds

Preparation of Zirconia Promoted Sulfated Titania System with High Catalytic Activity

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