The controllable preparation of nano-gold catalyst maintains a challenge. Except the parameters have been revealed before, here we'd like to show that controllable preparation of active nano-gold catalyst can be achieved using chlorine as an indicator. By tracing the chlorine concentration in the washing step, a series of Au/Fe2O3 catalysts were prepared with co-precipitation method. The applyi...

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,...

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the Hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. SBA-P...

the knoevenagel condensation of aromatic aldehydes with barbituric acid, dimedone and malononitrile occurred in the presence of bf3/nano-γ-al2o3 at room temperature in ethanol. this catalyst is characterized by powder x-ray diffraction (xrd), fourier transform infrared spectroscopy (ft-ir), thermal gravimetric analysis (tga), field emission scanning electron microscopy (fesem) and energy-disper...

12-Tungstophosphoric acid supported on silica-coated magnetic nano particles was prepared and characterized by transmission electron microscopy, scanning electron microscopy, powder X-ray diffraction and inductively coupled plasma atomic emission spectroscopy. Acidity of the catalysts was measured by potentiometric titration with n-butylamine. Catalytic activity of the prepared sample was evalu...

Two simple protocols for the synthesis of tetrahydrobenzo[a]xanthenes-11-ones using nano silica phosphoric acid are reported. Short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.

A proper, atom-economical, straightforward one-pot multicomponent synthetic route for the synthesis of benzopyranophenazines has been presented by the reaction of hydroxynaphthoquinone, o-phenylenediamine, benzaldehydes, and malononitrile with crosslinked sulfonated polyacrylamide (Cross-PAA-SO3H) attached to nano-Fe3O4as an efficient heterogeneous soli...

two simple protocols for the synthesis of three-component condensation reaction of an aldehyde, β-ketoester and urea or thiourea to obtain the 3, 4-dihydropyrimidin-2(1h)-ones (thiones) using nano silica phosphoric acid are reported. short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.

Pyrano [2,3-d] pyrimidinone derivatives have received considerable interest from the pharmaceutical industry due to their wide range of interesting biological and therapeutic properties. Nano Al2O3 was found to be a highly efficient solid acid catalyst for the preparation of pyrano [2,3-d] pyrimidinone derivatives from the reaction of barbituric acid, aryl aldehyde and mal...

Effective solid acid catalysts play a key role to produce high-quality biodiesel through triglyceride transesterification. The present work describes a facile technique for the synthesis of a high-performing sulfonated multi-walled carbon nanotube (S-MWCNTs) solid acid catalyst for fatty acid ethyl ester (biodiesel) production. The results indicated that S-MWCNTs possessed high acidity due to t...