The Effect of K and Acidity of NiW-Loaded HY Zeolite Catalyst for Selective Ring Opening of 1-Methylnaphthalene.

Bi-functional catalysts were prepared using HY zeolites with various SiO2/Al2O3 ratios for acidic function, NiW for metallic function, and K for acidity control. 1-Methylnaphthalene was selected as a model compound for multi-ring aromatics in heavy oil, and its selective ring opening reaction was investigated using the prepared bi-functional catalysts with different levels of acidity in a fixed bed reactor system. In NiW/HY catalysts without K addition, the acidity decreased with the SiO2/Al2O3 mole ratio of the HY zeolite. Ni1.1W1.1/HY(12) catalyst showed the highest acidity but slightly lower yields for the selective ring opening than Ni1.1W1.1/HY(30) catalyst. The acidity of the catalyst seemed to play an important role as the active site for the selective ring opening of 1-methylnaphthalene but there should be some optimum catalyst acidity for the reaction. Catalyst acidity could be controlled between Ni1.1W1.1/HY(12) and Ni1.1W1.1/HY(30) by adding a moderate amount of K to Ni1.1W1.1/HY(12) catalyst. K0.3Ni1.1W1.1/HY(12) catalyst should have the optimum acidity for the selective ring opening. The addition of a moderate amount of K to the NiW/HY catalyst must improve the catalytic performance due to the optimization of catalyst acidity.

Aromatization of Ethanol Over Desilicated ZSM-5 Zeolites: Effect of Pore Size in the Mesoporous Region.

Mesoporous ZSM-5 zeolites were obtained from microporous ZSM-5 by desilication using aqueous NaOH solutions, and their catalytic activity in the aromatization of ethanol was investigated in order to understand the effects of pore size, in the mesoporous region, on the product distribution and stability of the catalysts. Mesopores generally enhanced the selectivities towards aromatics and stability for aromatization. Mesopores with a maximum pore diameter of around 13 nm were the most effective in the aromatization process (especially for benzene and toluene), suggesting that pore-diameter optimization is necessary for efficient catalysis such as aromatization.

Selective Ring Opening of 1-Methylnaphthalene Over NiW-Supported Catalyst Using Dealuminated Beta Zeolite.

Nanoporous Beta zeolite was dealuminated by weak acid treatment for reducing the acidity. Bi-functional catalysts were prepared using commercial Beta zeolites and the dealuminated zeolites for acidic function, NiW for metallic function. 1-Methylnaphthalene was selected as a model compound for multi-ring aromatics in heavy oil, and its selective ring opening reaction has been investigated using the prepared bi-functional catalysts with different acidity in fixed bed reaction system. The dealuminated Beta zeolites, which crystal structure and nanoporosity were maintained, showed the higher SiO2/Al2O3 ratio and smaller acidity than their original zeolite. NiW-supported catalyst using the dealuminated Beta zeolite with SiO2/Al203 mole ratio of 55 showed the highest performance for the selective ring opening. The acidity of catalyst seemed to play an important role as active sites for the selective ring opening of 1-methylnaphthalene but there should be some optimum catalyst acidity for the reaction. The acidity of Beta zeolite could be controlled by the acid treatment and the catalyst with the optimum acidity for the selective ring opening could be prepared.

Mesoporous Carbon Supported Rh Nanoparticle Catalysts for the Production of C2+ Alcohol from Syngas.

Uniform rhodium nanoparticles (NP) with three different particle sizes (1.9, 2.4, and 3.6 nm) were prepared via a polyol method with rhodium (III) acetylacetonate, poly(vinylpyrrolidone) with different concentrations of sodium citrate. The prepared Rh nanoparticles were impregnated into the ordered mesoporous carbon supports with two different pore structures (2D hexagonal and 3D cubic). The prepared Rh nanoparticle-supported ordered mesoporous carbons (OMCs) were introduced as catalysts for the CO hydrogenation of syngas to produce C2 higher alcohols. The characteristics of the Rh nanoparticle-supported ordered mesoporous carbons catalysts were analyzed through transmission electron microscopy, powder X-ray diffraction, and N2 physisorption analysis. The catalytic tests of the catalyst were performed using a fixed-bed reactor. The results revealed that the catalysts exhibited the different catalytic activity and selectivity of higher alcohols, which could be attributed to the different OMC structures, the nanoparticle size of Rh, and aggregation of Rh nanoparticles during the reaction.

Ring Opening of Naphthenic Molecules Over Metal Containing Mesoporous Y Zeolite Catalyst.

Mesoporous Y zeolite (Meso-Y) with a uniform mesopore was synthesized via pseudomorphic syn- thesis. The Meso-Y supported Ni-W catalyst (NiW/Meso-Y) was introduced as a catalyst for the selective ring opening of naphthenic rings. The catalytic test for the ring opening of naphthalene as a model compound of multi-ring aromatics was performed using a batch-type reaction system with both sulfided 20 wt% NiW/Meso-Y and NiW/Y catalysts under different reaction conditions. The catalytic results reveal that the Meso-Y supported NiW catalyst experiences a naphthalene conversion similar to the NiW/Y catalyst, but the NiW/Meso-Y catalyst has higher product yields for BTEX (benzene, toluene, ethyl benzene, and xylene) and the middle distillate than those of the NiW/Y catalyst at a low reaction temperature. These results suggest that the mesoporosity of the NiW/Meso-Y catalyst is more advantageous for the ring opening reaction of multi-ring aromatics due to the easier access for the bulky molecules compared to the NiW/Y catalyst.

Conversion to Aromatic Hydrocarbons Over Nano- and Micro-Sized Particle La/Zn/HZSM-5 Catalysts.

The effect of the template of HZSM-5 and its synthesis method on the catalytic conversions of ethanol to aromatic hydrocarbons has been investigated over a 0.8%Zn/0.6%La/HZSM-5 (Si/Al2 = 50) catalyst in a fixed-bed flow reactor under operating conditions of T = 710 K, P = 1 bar, and WHSV = 0.8 hr(-1). Nano- and micro-size HZSM-5 were prepared by hydrothermal and microwave synthesis with different templates: TPAOH, TPABr, and HMDA. Zinc and lanthanum modified HZSM-5 catalysts were prepared by a simple co-impregnation method. It was found that the size of the particles and the crystal structure of HZSM-5 were influenced by the template type and synthesis method. When using the TPAOH template, the nano-sized particles were prepared by microwave synthesis, whereas HZSM-5 prepared from TPABr and HMDA by a hydrothermal method, were composed of cubic shaped nanocrystals inside a micro-sized particle. The effect of the template on the selectivity to aromatics over a La/Zn/HZSM-5 catalyst was shown as follows: HMDA > TPABr > TPAOH.

Isomerization of Higher Alkane Over Platinum Supported on Nanoporous Materials.

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.

Hydroisomerization of n-dodecane over Pt/Al-MCM-48 catalysts.

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.

Synthesis of mesoporous SAPO-34 zeolite from mesoporous silica materials for methanol to light olefins.

Mesoporous SAPO-34 zeolites were synthesized by using as-prepared mesoporous silica material as both silica source and mesopore tailor. The mesoporous SAPO-34 zeolite materials thus obtained are characterized by a series of different techniques, including poweder X-ray diffraction pattern, nitrogen physisorption analysis, scanning electron micrograph, temperature programmed desorption of ammonia, and inductively coupled plasma atomic emission spectrometry. The resultant mesoporous SAPO-34 crystals exhibit sphere-like particle with zeolite layer units. The mesopore size distribution and particle size can be changed by amounts of silica source and water. The methanol-to-olefins (MTO) reactions using these mesoporous SAPO-34 zeolites are carried out with a fixed-bed reactor. Catalytic tests exhibit that the mesoporous SAPO-34 zeolite materials show high catalytic activity compared with the conventional SAPO-34 for MTO reaction. The better catalytic activity and longer life time of the mesoporous SAPO-34 catalysts in MTO are mainly due to the existence of the mesoporosity of SAPO-34 with small particle size.

Structural influence of ordered mesoporous carbon supports for the hydrogenation of carbon monoxide to alcohols.

A series of ordered mesoporous carbon materials (OMCs) possessing well-ordered nanoporosity with different mesopore structures were synthesized by the template-synthesis route. Two different pore strucutes (2-dimensional hexagonal and 3-dimensional cubic structures) and two different framework-configurations (rod-type and hollow-type carbon frameworks) are prepared by using the two different silica templates and synthetic conditions. The ordered mesoporous carbon supported promoted-rhodium catalysts were preparted by an incipient wetness method. The promoted Rh-OMC catalysts are tested by a fixed bed reactor for the catalytic conversion of syngas-to-alcohols. The characteristics of the promoted Rh-OMCs catalysts were scrutinized through a series of different techniques, including transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and N2 sorption analysis, and the catalytic performance was tested in a fixed-bed reactor. It was found that the promoted Rh-OMC catalysts exhibited the different catalytic activity and selectivity of alcohols, which could be attributed to the size of metal nanoparticles being confined by the different mesostructure of OMCs.

Effect of Pt particle size on the hydroisomerization of n-dodecane over Pt/Ai-SBA-15 catalysts.

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.

Effect of the preparation method of support on the aqueous phase reforming of ethylene glycol over 2 wt% Pt/Ce0.15Zr0.85O2 catalysts.

The effect of catalyst support on the aqueous phase reforming of ethylene glycol over supported 2 wt% Pt/Ce0.15Zr0.85O2 catalysts have been investigated. Various types of Ce0.15Zr0.85O2 mixed oxides were prepared by hydrothermal precipitation (CZH), modified precipitation (CZM), co-precipitation (CZC), sol-gel (CZS) methods, respectively. Catalysts were characterized by XRD, N2 sorption analysis, and cyclohexane dehydration for relative metal dispersion. The support effect on the activity of 2 wt% Pt/Ce0.15Zr0.85O2 catalysts with different preparation method was given as follows: CZH < CZM < CZC < CZS. Pt/Ce0.15Zr0.85O2 (CZS) catalyst showed good catalytic activity for APR reaction due to its high metal dispersion and reducibility. The effect of reaction conditions such as reaction temperature, weight hourly space velocity (WHSV) was also studied. The hydrogen production rate and hydrogen yield increased in proportion to the reaction temperature and corresponding system pressure, whereas WHSV did not affect.

Synthesis of mesoporous SAPO-34 molecular sieves and their applications in dehydration of butanols and ethanol.

Microporous SAPO-34 molecular sieves were hydrothermally synthesized with microwave irradiation in the presence of tetraethylammonium hydroxide (TEAOH) as a template. SAPO-34 molecular sieves with mesoporosity were also prepared in the presence of carbon black as a hard template. By increasing the content of the carbon black template in the synthesis, the mesopore volume increased. Dehydration of alcohols (butanols and ethanol) was carried out with the synthesized SAPO-34 molecular sieves, and the lifetime of the catalysts for the dehydration reaction increased as the mesoporosity increased. Moreover, the performance of the microporous catalyst synthesized with microwave was better than that of the catalyst obtained with conventional electric heating. The relative performance of the catalytic dehydration may be explained by the mesoporosity and the crystal size. Therefore, it may be concluded that small-sized SAPO-34 molecular sieves with high mesoporosity can be produced efficiently with microwave irradiation in the presence of carbon black template, and the molecular sieves are effective in the stable dehydration of alcohols.

Hydroconversion of n-dodecane over nanoporous catalysts.

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.

Pressure monitoring of multilayer inelastic bandaging and the effect of padding in breast cancer-related lymphedema patients.

OBJECTIVE: This study of pressure monitoring of multilayer inelastic bandaging and the effect of padding in breast cancer-related lymphedema patients aimed to measure the resting and working sub-bandage pressures in compression therapy for lymphedema patients and to determine whether applying additional padding has an additional effect in volume reduction of the limb. DESIGN: Forty-eight patients with breast cancer who were beginning complex decongestive therapy for lymphedema were included. In 24 patients, padding was added to the forearm. A short-stretch bandage with or without padding was applied to the affected arm. The working pressure was measured while the patients squeezed a rubber device. The forearm limb circumference was measured before and after 2 wks of treatment. RESULTS: The mean (SD) of the resting pressure was 36.3 (2.2) mm Hg without padding and 49.5 (3.2) mm Hg with padding. The mean (SD) of the working pressure was 9.5 (3.7) mm Hg without padding and 24.3 (9.1) mm Hg with padding (P < 0.05). The volume loss after treatment was significantly greater in the group with added padding (P < 0.05). CONCLUSIONS: The working pressure during exercising with a force of 50 Pa is approximately 10 mm Hg with a short-stretch bandage applied. Adding a pad increases both the resting and the working pressure and also seems to be effective in increasing volume reduction of the limb.

Production of biohydrogen by aqueous phase reforming of polyols over platinum catalysts supported on three-dimensionally bimodal mesoporous carbon.

Now in 3D! Three-dimensionally bimodal carbons (3D-BMC) with mesopores of tunable size (controlled through the polymerization of the carbon precursor) are synthesized. After loading with platinum, the catalysts are used in aqueous phase reforming of polyols, and show superior performance in terms of carbon conversion, hydrogen yield, selectivity, and hydrogen production rate compared to platinum catalysts supported on activated carbon or two-dimensional CMK-3.

Utilization of a by-product produced from oxidative desulfurization process over Cs-mesoporous silica catalysts.

We investigated the use of Cs-mesoporous silica catalysts to upgrade a by-product of oxidative desulfurization (ODS). Cs-mesoporous silica catalysts were characterized through N2 adsorption, XRD, CO2-temperature-programmed desorption, and XRF. Cs-mesoporous silica prepared by the direct incorporation method showed higher catalytic performance than a Cs/MCM-41 catalyst by impregnation method for the catalytic decomposition of sulfone compounds produced from ODS process.

Prediction of treatment outcome with bioimpedance measurements in breast cancer related lymphedema patients.

OBJECTIVE: To investigate the usefulness of bioimpedance measurement for predicting the treatment outcome in breast cancer related lymphedema (BCRL) patients. METHOD: Unilateral BCRL patients who received complex decongestive therapy (CDT) for 2 weeks (5 days per week) were enrolled in this study. We measured the ratio of extracellular fluid (ECF) volume by using bioelectrical impedance spectroscopy (BIS), and single frequency bioimpedance analysis (SFBIA) at a 5 kHz frequency before treatment. Arm circumferences were measured at 10 cm above and below the elbow before and after treatment. We also investigated whether there is correlation between ECF ratio and SFBIA ratio with the change of arm circumference after CDT. RESULTS: A total of 73 patients were enrolled in this study. The higher ECF ratio was significantly correlated with higher reduction of arm circumference at both above and below the elbow after treatment, but the higher SFBIA ratio was correlated only with the higher reduction of arm circumference below the elbow. CONCLUSION: These results show that ECF volume measurements and SFBIA before treatment are useful tools for predicting the outcome of patients with lymphedema. We concluded that ECF volume measure can be used as a screening tool for predicting treatment outcome of BCRL patients.

Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound.

Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated.

Catalytic removal of sulfur dioxide from dibenzothiophene sulfone over Mg-Al mixed oxides supported on mesoporous silica.

Dibenzothiophene sulfone (DBTS), one of the products of the oxidative desulfurization of heavy oil, can be removed through extraction as well as by an adsorption process. It is necessary to utilize DBTS in conjunction with catalytic cracking. An object of the present study is to provide an Mg-Al-mesoporous silica catalyst for the removal of sulfur dioxide from DBTS. The characteristics of the Mg-Al-mesoporous silica catalyst were investigated through N2 adsorption, XRD, ICP, and XRF. An Mg-Al-mesoporous silica catalyst formulated in a direct incorporation method showed higher catalytic performance compared to pure MgO during the catalytic removal of sulfur dioxide from DBTS. The higher dispersion of Mg as well as the large surface area of the Mg-Al-mesoporous silica catalyst strongly influenced the catalyst basicity in DBTS cracking.