نتایج جستجو برای: nanoporous acid catalyst

تعداد نتایج: 788848  

2007
R. A. E. N. E. H.

Previous studies on hydroformylation of methyl oleate with rhodium and triphenylphosphine or triphenylphosphite have led to a laboratory process for recycling the precious metal catalyst. Another catalyst recycling process has now been studied as the basis for converting commercially available oleic acid into the enol ether of methyl formylstearate. The process involves one-step esterification-...

Journal: :iranian journal of science and technology (sciences) 2013
r. sardarian

14-aryl- and 14-alkyl-14-h-dibenzo [a,j]xanthenes are prepared from the reaction of aromatic- and aliphaticaldehydes with β-naphthol in the presence of catalytic amounts of 4-dodecylbenzenesulfonic acid(dbsa) as asurfactant-type brønsted acid catalyst in toluene and under solvent-free conditions in excellent yields and shortreaction times. the catalyst was recovered and reused for five successi...

2016
Keren Jiang Chin Li Cheung

Cerium oxide, or ceria (CeO x : x = 1.5 to 2), has been widely used as a heterogeneous catalyst. Ceria has several properties make it high catalytic active: the fluctuating valence of cerium, the high oxygen storage capacity and high oxygen mobility in the nonstoichiometric ceria. With the high abundance of cerium on earth crust, ceria is a highly effective alternative of the noble metal cataly...

Journal: :Journal of the American Chemical Society 2011
Jianfeng Ye Wen Liu Jinguang Cai Shuai Chen Xiaowei Zhao Henghui Zhou Limin Qi

Unique spindle-shaped nanoporous anatase TiO(2) mesocrystals with a single-crystal-like structure and tunable sizes were successfully fabricated on a large scale through mesoscale assembly in the tetrabutyl titanate-acetic acid system without any additives under solvothermal conditions. A complex mesoscale assembly process involving slow release of soluble species from metastable solid precurso...

Nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. The catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. The size of nanoparticles were observed with SEM.All prepared compounds w...

A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in w...

2016
Haiming Cheng Changqing Hong Xinghong Zhang Huafei Xue Songhe Meng Jiecai Han

The desire for lightweight nanoporous materials with high-performance thermal insulation and efficient anti-ablation resistance for energy conservation and thermal protection/insulation has greatly motivated research and development recently. The main challenge to synthesize such lightweight materials is how to balance the relationship of low thermal conductivity and flame retardancy. Herein, w...

Journal: :Electrochimica Acta 2021

• Biomass-derived carbons are appropriate precursors for fuel cell electrocatalysts. Microporosity and graphitic domains play a determining role in electroactivity. Catalysts become active upon two thermal treatments one acid etching. Fe-N 4 -C nitrogen functionalities created on activated carbon matrix. Biomass from agricultural by-products is gaining increasing interest as cheap abundant prec...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1997
fereydoon milani nejad mohammad rahimizadeh hassan ali mirshahi

the catalytic oxidation of toluene to benzoic acid in the liquid phase has been studied in an un-stirred tank reactor. low concentration of acetic acid was added in order to increase the solubility of the catalyst in toluene. the dependence of the rate of reaction on the concentration of toluene catalyst and oxygen pressure was studied. it has been suggested that liquid phase oxidation of tolue...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

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