Catalytic Activity of Dehydrogenation of Methanol to MF over Cu/MCM-41 and Cu-ZnO/MCM-41 Prepared by Impregnation and Grinding

2011 ◽  
Vol 396-398 ◽  
pp. 730-733
Author(s):  
Guo Ru Li ◽  
Gong Li ◽  
Shu Xi Zhou ◽  
Hui Juan Tong
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Molecular Sieves ◽  
Conversion Rate ◽  
Methyl Formate ◽  
Methanol Conversion ◽  
N2 Adsorption ◽  
Flow Microreactor ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract. Using MCM-41 molecular sieves as the support, Cu-ZnO/MCM-41 and Cu/MCM-41 catalysts were prepared by impregnation and grinding. The catalysts were characterized by XRD, N2 adsorption-desorption and TPR methods. The catalytic activity of the dehydrogenation of methanol to methyl formate (MF) was evaluated using the flow microreactor under atmospheric pressure. According to the results, the catalyst prepared by impregnation had a better selectivity for the MF, but a lower methanol conversion rate. However, the product's selectivity could be improved by adding ZnO additive while the methanol conversion rate was reduced. For Cu/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 20.18% and 24.13% respectively at 250°C and the MF selectivity was 73.75% and 67.35% respectively. Likewise for Cu-ZnO/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 15.28% and 18.83% respectively at 250°C and the MF selectivity was 81.31% and 75.32% respectively.

Catalytic Activity of Dehydrogenation of Methanol to MF over Cu/SBA-15 and Cu-ZnO/SBA-15 Prepared by Grinding and Impregnation

2012 ◽  
Vol 608-609 ◽  
pp. 1476-1479
Author(s):  
Min Jian Huang ◽  
Gong Li ◽  
Guo Ru Li
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieve ◽  
Conversion Rate ◽  
Methyl Formate ◽  
Nitrogen Adsorption ◽  
Methanol Conversion ◽  
Reduction Temperature ◽  
Catalytic Activities ◽  
Adsorption Desorption

Using SBA-15 molecular sieve as the support, Cu/SBA-15 and Cu-ZnO/SBA-15 catalysts were prepared by grinding and impregnation. They were characterized by XRD, TEM, TPR and nitrogen adsorption/desorption methods. Their catalytic activities of the dehydrogenation of methanol to methyl formate (MF) were studied and compared.The results indicated that the Cu and ZnO in the catalysts prepared by grinding had a worse dispersity than that prepared by impregnation. However, the reduction temperature of the CuO in the catalysts prepared by grinding was obviously lower than that prepared by impregnation and the selectivity to MF can be improved with the adding of ZnO. The experiments showed that the methanol conversion rate and selectivity to MF were 15.23% and 79.81% at 270°C for Cu-ZnO/SBA-15-G prepared by grinding, respectively. For Cu-ZnO/SBA-15-I prepared by impregnation, the methanol conversion rate and selectivity to MF were 13.41 % and 81.31% respectively.

Catalytic Activity of Heteropolytungstic Acid Encapsulated into Mesoporous Material Structure

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Gonul Gunduz ◽  
Rayna P. Dimitrova ◽  
Selahattin Yilmaz
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Mesoporous Material ◽  
Heteropoly Acid ◽  
Methanol Conversion ◽  
Tungstophosphoric Acid ◽  
Material Structure ◽  
Acetate Oxidation ◽  
Mcm 41 ◽  
Model Reactions

The paper presents a spectroscopic and catalytic study of encapsulated Keggin type heteropoly acid (12-tungstophosphoric acid, HPW) in the mesopores of MCM-41 molecular sieves. Nitrogen physisorption, FTIR, SEM, XRD and catalytic methods have been used to characterize and compare the properties of the samples. Methanol conversion, ?-pinene isomerization and ethyl acetate oxidation have been applied as model reactions for the evaluation of acid site activity. The combined physicochemical and catalytic investigations clearly show that the introduction of 12-tungstophosphoric acid into MCM-41 causes significant changes in the properties of the sample.

scholarly journals Synthesis of Small-Sized SAPO-34 Crystals with Varying Template Combinations for the Conversion of Methanol to Olefins

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 570 ◽  
Author(s):  
Yanjun Zhang ◽  
Zhibo Ren ◽  
Yinuo Wang ◽  
Yinjie Deng ◽  
Jianwei Li
Keyword(s):  
Molecular Sieves ◽  
Crystal Size ◽  
Ammonium Hydroxide ◽  
Methanol Conversion ◽  
29Si Mas Nmr ◽  
Hydrothermal Conditions ◽  
N2 Adsorption ◽  
Ft Ir ◽  
Ir Analysis ◽  
Adsorption Desorption

SAPO-34 molecular sieves were synthesized under hydrothermal conditions using different combinations of tetraethyl ammonium hydroxide (TEAOH)/morpholine (Mor)/triethylamine (TEA) as templates, with different silicon:aluminum ratios. The physicochemical properties of the synthesized SAPO-34 were characterized using XRD, SEM, N2 adsorption–desorption, XRF, TG, NH3-TPD, FT-IR, and 29Si MAS NMR analyses. According to the SEM and the N2 adsorption–desorption of the catalysts produced by the ternary template exhibited a larger surface area and a smaller crystal size than those produced by the single or binary templates. The FT-IR analysis indicated the increased acidity of the catalyst prepared by the ternary template. A high activity and selectivity to olefins (C2= + C3=) and an optimal silicon to aluminum ratio of 0.4 were obtained from the catalyst synthesized with the ternary template. At the reaction temperature of 450 °C, the methanol conversion approached 100% and the ethylene–propylene selectivity and the lifetime of the catalyst reached maximums of 89.15% and 690 min, respectively.

Synthesis of Al-Containing Mesoporous Molecular Sieves and their Catalytic Performance to Isomerization Reaction of Endo-Tetrahydrodicyclo-Pentadiene

2011 ◽  
Vol 233-235 ◽  
pp. 234-237 ◽  
Author(s):  
Sa Liu ◽  
Jian Wei Guo ◽  
Chu Fen Yang ◽  
Long Huan Li ◽  
Yi Hua Cui
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Catalytic Performance ◽  
Mesoporous Molecular Sieves ◽  
Isomerization Reaction ◽  
Inorganic Acid ◽  
Ft Ir ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Mcm 41

Al-containing mesoporous molecular sieves(Al-MCM-41) were synthesized at ambient temperature. The structures of samples were characterized by XRD, N2-adsorption/desorption isotherms and FT-IR, etc. The evaluation results showed that Al-MCM-41 had higher catalytic activity for isomerization conversion of endo-tetrahydrodicyclo-pentadiene (endo-TCD) into exo-tetrahydrodicyclo-pentadiene (exo-TCD) and adamantane (AdH). Loading inorganic acid on the surface of Al-MCM-41 led increase of its catalytic activity and the yield of adamantane.

Vanadium-Chromium Oxide: Effective Catalysts for Ammoxidation of 3-Picoline

2013 ◽  
Vol 634-638 ◽  
pp. 624-627 ◽  
Author(s):  
Feng Jiang ◽  
Wei Xu ◽  
Lei Niu ◽  
Guo Min Xiao
Keyword(s):  
Raman Spectroscopy ◽  
Catalytic Activity ◽  
Chromium Oxide ◽  
Atmospheric Pressure ◽  
High Selectivity ◽  
Surface Acidity ◽  
N2 Adsorption ◽  
Composite Oxide ◽  
Highly Active

Bulk vanadium-chromium oxide (VCrO) catalyst was prepared and characterized by N2 adsorption, XRD, NH3-TPD, H2-TPR, and Raman spectroscopy. XRD and Raman results showed that the VCrO catalyst was a kind of VV-CrIII composite oxide mainly consisted of crystalline V2O5 and CrVO4-Ⅲ (orthorhombic). NH3-TPD and H2-TPR results revealed that this catalyst had negligible surface acidity, and was easily reduced due to the formation of CrVO4-Ⅲ. Their catalytic activity was evaluated in the ammoxidation of 3-picoline to nicotinonitrile. Catalytic results showed that the bulk VCrO catalyst was highly active and selective; the nicotinonitrile selectivity and yield was up to 96.1%, 88.2% respectively at atmospheric pressure and 360 °C. The high selectivity was related closely to the low surface acidity of the catalyst.

Synthesis, characterization and catalytic activity of actinide Th-MCM-41 and U-MCM-41 hexagonal packed mesoporous molecular sieves

2001 ◽  
Vol 171 (1-2) ◽  
pp. 229-241 ◽  
Author(s):  
Rodica Tismaneanu ◽  
Biswajit Ray ◽  
Rafael Khalfin ◽  
Rafi Semiat ◽  
Moris S. Eisen
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Mesoporous Molecular Sieves ◽  
Mcm 41

Nanosized Titanium Oxynitride and Molybdenum Oxynitride Particles Assembled in Mesoporous Silica MCM-41

2006 ◽  
Vol 510-511 ◽  
pp. 138-141 ◽  
Author(s):  
Shan Zheng ◽  
Lian Gao
Keyword(s):  
Composite Materials ◽  
Mesoporous Silica ◽  
Mesoporous Materials ◽  
N2 Adsorption ◽  
Xps Spectra ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Nitridation Temperature ◽  
Mcm 41

Titanium oxynitride and molybdenum oxynitride assembled in the pores of mesoporous materials were achieved by nitriding titania-modified MCM-41 and molybdena-modified MCM-41 at 800°C for 3 hours under flowing NH3 atmosphere. XRD, XPS and N2 adsorption-desorption isotherms were employed to characterize the structure of the composite materials. The results showed that the nanosized TiOxNy and MoOxNy particles were assembled in mesoporous silica MCM-41 with the restrict mesopores. The hexagonal periodicity of the parent MCM-41 materials was maintained upon assembly at the provided nitridation temperature. The exact formation was TiO0.4N0.8 in MCM-TiOxNy, and MoO1.7N0.57 in MCM-MoOxNy, which were calculated from the data in XPS spectra of Ti 2p and Mo 3d.

Comparison of TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 Hybrid Catalysts in Characteristics and Photodegradation of Tetramethylammonium

2010 ◽  
Vol 93-94 ◽  
pp. 22-26 ◽  
Author(s):  
Surachai Artkla ◽  
Won Yong Choi ◽  
Jatuporn Wittayakun
Keyword(s):  
Irradiation Time ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Adsorption Desorption ◽  
Two Hybrid ◽  
Mcm 41

This work compared properties and catalytic performance of two hybrid photocatalysts, TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 prepared by loading nanoparticles of TiO2 (10 wt.%) on MCM-41 synthesized with rice husk silica and tetraethyl orthosilicate respectively. The supports and catalysts were characterized by X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy and zeta potential. The photocatalytic activities of the TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 for the degradation of tetramethylammonium (TMA) in aqueous slurry were similar with a complete conversion after irradiation time of 90 min at pH 7.

The Performance of the Cu-Zn/CeO2 Catalysts in the Steam Reforming of Methanol Reaction

2011 ◽  
Vol 324 ◽  
pp. 157-161 ◽  
Author(s):  
Mary Mrad ◽  
Cédric Gennequin ◽  
Antoine Aboukaïs ◽  
Edmond Abi-Aad
Keyword(s):  
Catalytic Activity ◽  
Steam Reforming ◽  
Conversion Rate ◽  
Methanol Conversion ◽  
Impregnation Method ◽  
Copper Species ◽  
Steam Reforming Of Methanol ◽  
Optimum Content

The performances of different xCu10Ce and xZn10Ce (x = 1, 3, and 5) catalysts prepared by impregnation method then pelletised, were investigated in the steam reforming of methanol (SRM) under a GHSV = 15500 h-1 with H2O/CH3OH = 2. The impregnation of copper over ceria supports shows better results than that of zinc. The catalytic activity in the Cu-based depends on the dispersion of the copper species. The methanol conversion rate is related to the formation of an optimum content of reduced copper species.

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