ABSTRACT
Tetrahydrotricyclopentadine (THTCPD) has been used as a fuel with a high energy density. THTCPD is produced by the hydrogenation of tricyclopentadiene (TCPD). In this study, Ru/nanoporous silica catalysts are utilized as a catalyst for TCPD hydrogenation. Ru/KIT-6 and Ru/SBA-15 show significantly higher activity compared to outcomes over the Ru/kieselguhr catalyst during TCPD hydrogenation. The nanoporous structures of Ru/KIT-6 and Ru/SBA-15 help to overcome the diffusion limitations of reactants and products during the TCPD hydrogenation process. In addition to the diffusion factors, the distribution of Ru crystallites on the support plays an important role in the TCPD hydrogenation activity.
ABSTRACT
One step reaction composed of DCPD oligomerization and DCPD oligomer isomerization was investigated over nanoporous Al-MCM-41 catalysts. The effects of aluminum grafting over MCM-41 on the catalyst characteristics were studied with respect to the synthesis of TCPD isomer. Physical and chemical properties of the catalysts were analyzed by N2 adsorption, temperature-programmed desorption of ammonia, and infrared spectroscopy of adsorbed pyridine. The overall number of acid sites as well as the number of Lewis acid sites increased with increasing of aluminum content over MCM-41. When utilizing MCM-41 and Al-MCM-41 as the catalyst, DCPD oligomerization reaction activity greatly increased compared to the thermal reaction. The highest TCPD isomer selectivity over the Al-MCM-41 catalyst with the highest aluminum content could be ascribed to the largest amount of acid sites. This study showed an increased level of TCPD isomer selectivity by an increasing level of Lewis acid sites through aluminum addition over MCM-41.
ABSTRACT
The objective of this study is to evaluate the catalytic potential of metal oxide/MCM-41 catalysts in dicyclopentadiene oligomerization/dicyclopentadiene oligomer isomerization. Molybdenum oxide, tungsten oxide, and titanium oxide were loaded on MCM-41 using the modified atomic layer deposition method. The amount of the acid site with weak strength has been increased through metal oxide deposition. The oligomer yield in dicyclopentadiene oligomerization/dicyclopentadiene oligomer isomerization did not change with increasing of the amount of acid site. The highest tricyclopentadiene isomer selectivity over the MoO3/MCM-41 catalyst could be attributed to having the highest overall number of acid sites among the catalysts.
ABSTRACT
The objective of this study is to evaluate the catalytic potential of Pt/MMZ-FER catalysts in hydroisomerization of long chain hydrocarbon. MMZ-FER, a nanoporous material produced from commercial ferrierite, was used as a support for the catalysts. The catalysts were characterized via X-ray powder diffraction, N2 adsorption, pyridine-IR, and the temperature-programmed desorption of ammonia. Hydroisomerization of n-dodecane was performed on Pt/MMZ-FER catalysts. Hydroisomerization requires platinum loading on MMZ-FER, even though the amount of platinum loaded (up to 1.2 wt%) did not greatly affect the process of hydroisomerization. Weak acid sites developed on the Pt/MMZ-FER samples induced less cracking of n-dodecane, resulting in an increase in selectivity for isomerization.
ABSTRACT
The objective of this study is to evaluate the catalytic potential of Pt/Al-MCM-48 catalysts in hydroisomerization of n-dodecane. The effects of the Si/Al ratio and platinum loading on the acid characteristics of Al-MCM-48 and the catalytic performance in n-dodecane hydroisomerization were analyzed. The catalysts were characterized by X-ray diffraction, nitrogen adsorption, infrared spectroscopy of pyridine adsorption, and temperature programmed desorption of ammonia. The number of weak strength acid sites on Al-MCM-48 increased with 0.5 wt% platinum loading. The weak strength acid sites of Pt/Al-MCM-48 catalysts were ascribed to Lewis acid sites, which can be confirmed by NH3-TPD and FTIR spectra of pyridine adsorption. Iso-dodecane can be produced with high selectivity in n-dodecane hydrosisomerization over Pt/Al-MCM-48 catalysts. This is attributed to the mild acidic properties of Pt/Al-MCM-48 catalysts.
ABSTRACT
The hydroisomerization of n-dodecane was carried out over platinum-impregnated Al-SBA-15 as a bifunctional catalyst. A range of Pt/Al-SBA-15 catalysts with a Pt particle size of 1.7, 2.9 and 7.1 were prepared to examine the effect of the Pt particle size on the activity and selectivity for the hydroisomerization of n-dodecane. The catalysts were characterized by transmission electron microscopy, X-ray diffraction, nitrogen adsorption, pyridine Fourier transform infrared spectroscopy and NH3 temperature programmed desorption. The hydroisomerization of n-dodecane was performed in a batch-type reactor at 350 degrees C and 20 bar. The Pt(2.9)/Al-SBA-15 catalyst showed the highest selectivity to iso-dodecane due to its largest number of medium strength Brønsted acid sites and the optimum ratio of metallic/acid sites.
ABSTRACT
Platinum catalysts impregnated on different nanoporous materials, Meso-MFI, Si-SBA-15 and AI-SBA-15, were synthesized, and the hydroconversion of n-dodecane over these catalysts was performed. The catalytic characteristics were analyzed by Brunauer-Emmett-Teller surface area, X-ray diffraction, N2-adsorption-desorption and temperature programmed desorption of NH3. The effects of operation parameters, such as temperature and pressure, on the catalytic activities were investigated. The catalytic activities were affected considerably by the acidic properties of the catalysts, temperature and pressure. Higher acidity, high temperature and low hydrogen pressure resulted in higher hydroconversion and facilitated hydrocracking. The weak acidity, low temperature and high hydrogen pressure resulted in lower hydroconversion and higher selectivity to i-dodecane.