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.

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.

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 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.

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.

Physicochemical characteristics of SAPO-34 molecular sieves synthesized with mixed templates as MTO catalysts.

In the present work, a variety of SAPO-34 catalysts have been prepared using various templates such as a single or mixtures of tetraethylammonium hydroxide (TEAOH), morpholine, diethylamine (DEA), triethylamine (TEA), dipropylamine (DPA), isopropylamine (IPA) and Diethanolamine (DEtA). It is shown that crystal morphology and physicochemical properties were affected by the kinds of templates and mixture contents. Especially, inexpensive SAPO-34 catalyst with good crystal properties and catalytic performance was obtained by using mixed template of DEA and TEAOH. Through N2 isotherm, XRD, SEM, NH3 TPD and 29Si-NMR techniques, the effect of mixed template on the crystal morphology, acidity and Si distribution were investigated. Catalytic activity and life stability of SAPO-34 in MTO reaction was improved by using mixed template because of the distinction of the crystal size, acidity and Si distribution.

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.

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.

Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS.

The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI) and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity.