Preparation of nanocrystalline γ-Al2O3 catalyst using different procedures for methanol dehydration to dimethyl ether

Keshavarz, Ahmad Reza; Rezaei, Mehran; Yaripour, Fereydoon

doi:10.1016/s1003-9953(10)60157-0

Cited by 45 publications

(15 citation statements)

References 14 publications

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“…Based on the earlier results, distinction between the weak, medium and strong acid sites can also be made by using desorption temperature. However, it is not possible to identify the nature of the acidic sites i.e., Lewis and Brønsted acid sites [43,44]. In our case, the total amount of acid sites is rising up with increasing the SiO2 loading.…”

Section: Characterisation Of Catalyst Powdersmentioning

confidence: 60%

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

et al. 2018

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Silica modified alumina was used in this study for coating of a cordierite monolith substrate with two different channel densities. The performance of the prepared monolith catalysts was evaluated in catalytic total oxidation of dichloromethane before and after Pt impregnation. The characteristics similar to the powder form catalysts were kept rather successfully after washcoating the monolith as evidenced by electron microscopy (FESEM) and N2 physisorption. A dichloromethane (DCM) conversion of higher than 80% at 500 °C was reached over all the catalysts with 200 cpsi. The maximum conversion was obtained with the catalyst containing 10 mol % of silica. The total amount of major byproducts (CO, CH3Cl and CH2O) were slightly decreased by increasing the silica loading, and remarkably after Pt impregnation. After impregnation of Pt, the HCl yields were increased for two samples with the higher loading of silica (10 and 15 mol %) and reached the maximum when silica loading was 10%. Even though Pt impregnation did not significantly affect the DCM conversion, it improved the selectivity. Comparison between the two substrates (200 and 600 cpsi) evidenced that the key parameters of the monolith influencing the DCM oxidation are low value of open fraction area, hydraulic diameter, thermal integrity factor and high value of mechanical integrity factor and geometric surface area.

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Section: Characterisation Of Catalyst Powdersmentioning

confidence: 60%

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

et al. 2018

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“…A significant increase in CO 2 conversion is achieved for the bimetallic catalyst (10La-20Ni/ Al 2 O 3 ). Also, it is seen the CH 4 selectivity of the monometallic catalyst was not affected by the increase in H 2 /CO 2 molar ratio, because at 350 C, CO 2 is completely converted to CH 4 [39] and at high temperature (more than 350 C), CH 4 selectivity was not changed. However, CH 4 selectivity for the bimetallic catalyst increased with increasing in H 2 /CO 2 molar ratio.…”

Section: Catalytic Performancementioning

confidence: 94%

“…A series of bimetallic catalysts (Ni and M‐Ni, M: Fe, Co, Ce, and La) supported on γ‐Al 2 O 3 were prepared by the wet impregnation method. The γ‐Al 2 O 3 support was synthesized by the sol–gel method according to the method described in our previous work . After the preparation of the catalyst support, according to the catalyst composition the prepared γ‐Al 2 O 3 was impregnated with aqueous solutions of nickel precursor (Ni(NO 3 ) 2 ·6H 2 O) and also the precursor of the second metals (Ce(NO 3 ) 9 ·6H 2 O, La (NO 3 ) 3 ·6H 2 O, Fe(NO 3 ) 3 ·9H 2 O, and Co(NO 3 ) 2 ·6H 2 O) with appropriate concentrations.…”

Section: Methodsmentioning

confidence: 99%

Preparation of Ni‐M (M: La, Co, Ce, and Fe) catalysts supported on mesoporous nanocrystalline γ‐Al₂O₃ for CO₂ methanation

Rahmani

Meshkani

Rezaei

2018

Env Prog and Sustain Energy

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In this study, the effect of adding second metals (La, Co, Ce, and Fe) to the nickel catalysts supported on mesoporous nanocrystalline γ‐Al2O3 in CO2 methanation was investigated. The co‐impregnation method was implemented to synthesize the bimetallic catalysts and the X‐ray diffraction, nitrogen adsorption/desorption, and temperature‐programmed reduction methods were employed for the catalyst characterization. According to the catalytic results, the addition of the second metals to the nickel‐based catalyst increased the catalyst reducibility and decreased the specific surface area from 143.3 to 107.9 m2/g and nickel crystallite size from 18.9 to 5.1 nm. Furthermore, the addition of 10 wt % lanthanum to the 20 wt % Ni/γ‐Al2O3 increased the CO2 conversion from 42% to 80.3% in methanation of carbon dioxide. Novelty or Significance: The study is focused on the preparation and evaluation of the La, Co, Ce, and Fe‐promoted Ni/Al2O3 nanocatalysts with mesoporous structure in CO2 methanation reaction. The results confirmed that the incorporation of these compounds in catalyst composition improved the reducibility of the nickel catalyst and decreased the BET area and Ni crystallite size and affected the CO2 conversion and CH4 selectivity. Among these metal oxides, the addition of La2O3 to the Ni/Al2O3 catalyst had the highest effect on the activity and selectivity of the Ni/Al2O3 catalyst. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 118–126, 2019

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“…The calculated crystallite sizes were found to be in the range of 1.5-2.5 nm. It is established [27][28][29][30][31] that conversion of aluminum hydroxide to single-phase nano-boehmite is dependent on many parameters such as temperature, nature of base, and type of aluminum salt. The present results showed that co-precipitation at 70˚C was able to produce nano-boehmite with high purity.…”

Section: X-ray Diffractionmentioning

confidence: 99%

Synthesis, characterization, and application of nano-perfluorooctyl alumina for adsorption of methyl tertiary-butyl ether (MTBE) from aqueous medium

Dehghani

Ebadi

Shafiei

et al. 2016

Desalination and Water Treatment

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In this work, adsorptions of Methyl tertiary-butyl ether (MTBE) onto two novel adsorbents, i.e. nano-perfluorooctyl alumina was prepared using nano-γ-alumina (nano-PFOAL G ) and nano-boehmite (nano-PFOAL B ) as the supports were investigated. The surface areas of the nano-γ-alumina and nano-boehmite were determined as 265.7 and 319.5 m 2 /g, respectively. The equilibrium adsorption behavior of the nanoadsorbents was studied for adsorption of (MTBE) in a wide range (100-1,750 mg/L) of aqueous phase concentrations. The maximum adsorption capacities were 46.0 and 44.4 mg MTBE/g adsorbent for nano-PFOAL G and nano-PFOAL B , respectively. The Freundlich, Langmuir, and Brunauer-Emmet-Teller (BET) isotherms were used for modeling of MTBE adsorption on nano-PFOAL G and nano-PFOAL B from aqueous medium. The experimental results of MTBE adsorption on the surface of nano-PFOAL adsorbents obeyed a type IV van der Waals adsorption trend, which can be modeled best by the BET isotherm up to pore filling concentration.

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Preparation of nanocrystalline γ-Al2O3 catalyst using different procedures for methanol dehydration to dimethyl ether

Cited by 45 publications

References 14 publications

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

Preparation of Ni‐M (M: La, Co, Ce, and Fe) catalysts supported on mesoporous nanocrystalline γ‐Al₂O₃ for CO₂ methanation

Synthesis, characterization, and application of nano-perfluorooctyl alumina for adsorption of methyl tertiary-butyl ether (MTBE) from aqueous medium

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Preparation of nanocrystalline γ-Al2O3 catalyst using different procedures for methanol dehydration to dimethyl ether

Cited by 45 publications

References 14 publications

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths

Preparation of Ni‐M (M: La, Co, Ce, and Fe) catalysts supported on mesoporous nanocrystalline γ‐Al2O3 for CO2 methanation

Synthesis, characterization, and application of nano-perfluorooctyl alumina for adsorption of methyl tertiary-butyl ether (MTBE) from aqueous medium

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Preparation of Ni‐M (M: La, Co, Ce, and Fe) catalysts supported on mesoporous nanocrystalline γ‐Al₂O₃ for CO₂ methanation