Papers by Keyword: Supported Catalyst

Abstract: Hydrocracking of Venezuelan heavy oil with no catalyst, dispersed Mo catalyst and Mo/Al₂O₃ catalyst were carried out to investigate the effect of Mo/Al₂O₃ catalyst component on the composition of residue hydrocracked product. Experimental data revealed that both dispersed Mo catalyst and Mo/Al₂O₃ catalyst improved the conversion of Venezuelan heavy oil and inhibited the formation of coke, but the two types of catalyst have the opposite effects on generation of light products. Besides, the activity metal suppressed the formation of isomerization product while the acidity support enhanced it.

Abstract: The intrinsic surface of carbon nanofiber (CNF) is important for supported catalyst preparation. The surface changes due to various techniques applied such as N₂ thermal and HNO₃ oxidation methods. The combination of different analyses is to observe the internal structure through Raman spectroscope, textural properties via N₂ physisorption and morphology of CNF using transmission electron microscope or through quantification of oxygen containing groups by acid base titration. As results, an extension of residence time increases the amount of amorphous and damages the structure of mesoporous CNF texture unexpectedly. The change from hydrophobic to hydrophilic surface of CNF is due to the growing number of oxygen. The surface area of CNF by HNO₃ treatment method produces 115.14m²/g which is higher than that of using thermal method.

Abstract: The catalyst Fe/SiO₂ was prepared by impregnation method and used as catalyst for treating the dye wastewater by catalytic wet peroxide oxidation method. The catalyst preparation process was optimized, and under the conditions of: the particle size of catalyst carrier was 0.125-0.200 mm, concentration of iron nitrate was 1.10mol/L, calcination temperature was 600 °C, and calcination time was 4h, the catalyst has higher activity and better stability in treating the wastewater.

Abstract: Hybrid compounds of multiwalled carbon nanotubes-alumina (MWCNT-Al₂O₃) were grown by chemical vapour deposition (CVD) method of methane. The catalyst effect and growth of the synthesis of the multiwalled carbon nanotubes-alumina (MWCNT-Al₂O₃) hybrid compound in three different supported catalysts (Ni, Co and Fe nitrates) were being compared. X-Ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) were employed for the characterization of the hybrid compound. The results revealed that the Ni nitrates catalysts showed a better growth rate performance than Co Nitrates and Fe Nitrates. With respect to the diameter of the MWCNT-Al₂O_3, the Fe nitrate showed lengthens in diameter compared to Co Nitrates and Ni Nitrates catalyst. This indicated that the growths of these carbon structures can be controlled and manipulated by the supported catalyst.

Abstract: A piperidine-functionalized poly (ethylene glycol) bridged dicationic ionic liquid PEG₈₀₀-DPIL(Cl) was synthesized and applied to catalyze the four-component Hantzsch reaction under solvent-free conditions and afford hydroquinolines with high to excellent yields. PEG₈₀₀-DPIL(Cl) could be recovered by simple workup and recycled for at least eight times without obvious activity loss.

Abstract: A novel macroporous polymer supported ruthenium (II) dimethyl phenyloxazoline (Ru (II)- dm-Pheox) catalyst has been developed by crosslinking polymerizing monomeric Ru (II)-dm-Pheox complex with styrene and 1,4-divinyl benzene (DVB) in the presence of 2,2-azobisizobutyronitrile (AIBN) and water. We evaluated the catalytic activity of our novel porous catalyst in the intermolecular N-H insertion of the commercially available ethyl diazoacetate (EDA) with various amines. The polymer supported catalyst showed excellent catalytic reactivity by delivering the amino acid derivatives in high yields after centrifugation.

Abstract: Pt catalysts have been researched and used for HI decomposition. Specifically, the effects of supports and reduction temperature on metal dispersion were investigated in this paper. Metal dispersion was high measured, in the order of Pt/Al₂O₃, Pt/ZrO₂, and Pt/SiO₂. HI conversion results coincided with the metal dispersion. With effect on reduction temperature, Pt dispersion was measured as 2.9 %, 26 %, and 60 % each 1173K, 973K, and 773 K. In addition, HI conversion presented 7.8%, 16.3%, and, 19.4% respectively. Consequently, Pt dispersion, influenced by supports and reduction temperature was considered to be crucial role in HI conversion.

Abstract: 12-tungstophosphoric acid was supported on amine-modified SBA-15 by impregnation. The structure and properties of the catalyst were characterized by FT-IR spectroscopy, X-ray diffraction, N2 adsorption-desorption, TEM,Raman spectra and NH3–TPD technology.the result confirmed the mesostructure for SBA-15 and the Keggin structure of the heteropolyanions was preserved. The tungstophosphoric acid can disperse in the pore of the support SBA-15/NH2, but the acidity of the catalyst reduced. The catalytic activities of the catalysts were evaluated for the esterification reaction of ethyl acetoacetate and ethylene glycol .and the catalysts supported on amine-modified SBA-15 show excellent reusability and selectivity.

Abstract: Supported cobalt is one of the common catalysts used in Fischer-Tropsch synthesis (FTS). Strong electrostatic adsorption (SEA) was employed to synthesize cobalt nano particles supported on silica. Cobalt nitrate was used as the catalyst precursor and non-porous silica spheres, which were synthesized using the modified Stöber method, were used as a catalyst support. Point of zero charge (PZC) for silica was determined using equilibrium pH at high oxide loading (EpHL) method. The optimum pH was determined by measuring cobalt uptake versus pH. High cobalt uptake at basic pH and low cobalt uptake at acidic pH indicates electrostatic interaction between the cobalt complexes in the precursor solution and the hydroxyl group on the support’s surface. Catalysts prepared at optimum pH were characterized using TPR, XPS and TEM. TPR shows reduction peak at high temperature (587°C) indicating strong interaction between cobalt and silica support. XPS shows presence of Co2+ species on the surface. TEM images of the Co/SiO2 at 5 wt% and 10 wt% cobalt loadings show fairly well-dispersed cobalt oxide nano particles on the spherical silica support with narrow particle size distribution. The findings suggest that SEA was deemed a suitable method to prepare supported cobalt catalysts.