Thorough investigation of varying template combinations on SAPO-34 synthesis, catalytic activity and stability in the methanol conversion to light olefin

Crystals of SAPO-34 molecular sieves were synthesized under hydrothermal conditions by using tetraethylammonium hydroxide, morpholine and a mixture of them as structure-directing agents.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.730 ◽

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.

Download Full-text

Catalytic Activity of Heteropolytungstic Acid Encapsulated into Mesoporous Material Structure

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1586 ◽

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.

Download Full-text

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

Catalysts ◽

10.3390/catal8120570 ◽

2018 ◽

Vol 8 (12) ◽

pp. 570 ◽

Cited By ~ 4

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.

Download Full-text

Catalytic Activity of Ni3Al Foils in Methanol Reforming

Materials Science Forum ◽

10.4028/www.scientific.net/msf.636-637.895 ◽

2010 ◽

Vol 636-637 ◽

pp. 895-900 ◽

Cited By ~ 8

Author(s):

P. Jozwik ◽

R. Grabowski ◽

Z. Bojar

Keyword(s):

Catalytic Activity ◽

Chemical Properties ◽

Methanol Conversion ◽

Advanced Materials ◽

Coarse Grained ◽

High Tech ◽

High Catalytic Activity ◽

Water Mixture ◽

Catalytic Coating ◽

Thin Foils

Intermetallic Ni3Al–based alloys (doped with zirconium and boron) represent a group of advanced materials with potential outstanding physical and chemical properties (such as high catalytic activity and structural stability in corrosive environments) that make them a considerable candidate for many high-tech applications. In this paper, the catalytic activity of fully dense Ni3Al-based thin foils (as thin as 50 m) possessing structures with micrometer or nanometer grain sizes is discussed. The examined material, without any additional catalytic coating, was successfully produced from as-cast coarse-grained sheets by heavy cold rolling and recrystallisation with an appropriately chosen set of parameters. The examination focuses on methanol and methanol/water mixture decomposition into H2 and CO at temperatures up to 530OC in a quartz reactor. Except for these products, a small amount (below 1%) of CO2 and dimethyl ether was observed. The catalyzed reaction began effectively at about 400OC, with a methanol conversion of about 90% or higher.

Download Full-text