Herein we investigate the use of CuO-ZnO-Al2O3 (CZA) with different solid acid catalysts (NH4ZSM-5, HZSM-5 or γ-Al2O3) for the production of dimethyl ether from syngas. It was found that of the solid acids, which are necessary for the dehydration function of the admixed system, the CZA/HZSM-5 bifunctional catalyst with a 0.25 acid fraction showed high stability over a continuous period of 212 h...

The preparation of nano-sized TiO2 by titanium tetraisopropoxide (Ti(OiPr)4) via sol-gelmethod using acid as a catalyst is investigated and the optimized conditions concerning theproportional amount of acid, water, alcohol is established by XRD and SEM. The effect ofcalcination temperature on phase transformation of TiO2 (rutile, anatase and brookite) wasdetermined by XRD. The smallest grain si...

An environmentally benign green protocol for the synthesis of 5-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones using Amberlyst 15 DRY as a recyclable catalyst has been developed. The use of resinous, nontoxic, thermally stable, and inexpensive Amberlyst 15 DRY, as a recyclable heterogeneous catalyst, makes the process simple with negligible chemical waste. Among the various solid acid catalysts ...

Platinum extraction from different secondary sources has been experimentally tested by many researchers. In this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. A variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

Composite solid propellants were prepared with and without nano-alloys (Ti-Co, Ti-Ni, Ti-Zn), where nano-alloys used as catalyst. These nano-alloys are prepared by hydrazine reduction method. Catalytic properties of these nanomaterials were measured on Ammonium perchorate/hydroxyterminatedpolybutadiene propellant by thermogravimetery analysis and differential thermal analysis. Both experimental...

During this study the application of Natrolite zeolite was investigated as a solid acid catalyst for efficient preparation of 5substituted 1H-tetrazole derivatives. Excellent yields of products were obtained with a wide range of substrates. After completion of the reaction, the catalyst was recovered by filtration and reused several times with only a slight decrease of activity observed under t...

Composite solid propellants were prepared with and without nano-alloys (Ti-Co, Ti-Ni, Ti-Zn), where nano-alloys used as catalyst. These nano-alloys are prepared by hydrazine reduction method. Catalytic properties of these nanomaterials were measured on Ammonium perchorate/hydroxyterminatedpolybutadiene propellant by thermogravimetery analysis and differential thermal analysis. Both experimental...