carbon nanotubes were synthesized over a series of zn-containing fe/alumina catalysts by chemical vapor deposition method at two reaction temperatures of 850 and 950 °c using methane as a carbon source. catalysts were synthesized by keeping fe concentration constant and varying zn concentration to study the effects of zn. the catalysts were characterized using x – ray powder diffraction and n2 ...

h-zsm-5 nano-zeolites were synthesized by hydrothermal method using tetrapropylammonium hydroxide (tpaoh) as a template in the presence of various tpabr concentrations. the effect of different tpabr/tpaoh molar ratios was studied on the catalytic performance of dehydration of methanol to dimethyl ether (dme) in a fixed bed reactor under the same operating conditions (t=300°c, p=1 atm, and whsv=...

Catalysts are important to the chemical industry and environmental remediation due to their effective conversion of one chemical into another. Among them, composite catalysts have attracted continuous attention during the past decades. Nowadays, composite catalysts are being used more and more to meet the practical catalytic performance requirements in the chemical industry of high activity, hi...

In recent years, Pillared InterLayered Clays (PILCs) have been widely used in several applications; in particular in adsorption and catalysis. The research interest in this family of solids has increased considerably. Clay minerals provide distinct nanometer-scaled layers and interlayers for engineering them as active catalysts. As such, strategic design and preparation has led to a variety of ...

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This paper reviews various types of heterogeneous acid-base catalysts for fragrances preparation. Catalytic activities of the various types of heterogeneous acid and base catalysts in fragrances preparation, i.e. nonzeolitic, zeolitic, and mesoporous molecular sieves, have been reported. Generally, heterogeneous acid catalysts are more commonly used in fragrance synthesis as compared to heterog...

Catalysts for the oxidation of H2O are an integral component of solar energy to fuel conversion technologies. Although catalysts based on scarce and precious metals have been recognized as efficient catalysts for H2O oxidation, catalysts composed of inexpensive and earth-abundant element(s) are essential for realizing economically viable energy conversion technologies. This Perspective summariz...

The epoxidation reaction using heterogeneous solid catalysts with H2O2 as oxidants are environmentally friendly routes to produce extensively useful epoxides which are traditionally obtained from capital-intensive or environmentally polluted processes. In this paper, various types of solid catalysts for the epoxidation of olefins with H2O2 as oxidants are reviewed. The efficient catalysts repor...

in this study, the slurry polymerization of ethylene over ticl4/mgcl2/alet3 was obtained. firstly, to obtain the optimum value of [al]/[ti], the effect of [al]/[ti] on polymerization rate and catalyst yield was studied. also, the effect of catalyst content on yielding, crystallization, melting point and density of product were obtained. to determine the order of reaction, the monomer pressure w...