نتایج جستجو برای: acid catalyst
تعداد نتایج: 784490 فیلتر نتایج به سال:
1566-7367/$ see front matter Crown Copyright 2 doi:10.1016/j.catcom.2010.01.010 * Corresponding authors. Tel./fax: +86 (21)6425382 E-mail addresses: [email protected] (J. Ren), w Wang). A novel carbon-based solid-acid catalyst was simply prepared for the first time by the thermal treatment of p-toluenesulfonic acid (TsOH) with D-glucose at 180 C in a sealed autoclave and it was proved to ha...
Studies on the synthesis of esters of natural origin fatty acids (oleic acid) and a branched synthetic isostearic acid derived from oleic acid with commercially available selected higher polyols in the presence of homogeneous metallic catalysts have been carried out. The effects of the synthesis temperature, molar ratio and the catalysts amount have also been studied. It was shown that higher f...
The selective oxidation of methoxy/methyl-substituted arenes to the corresponding benzoquinones has been first realized using aqueous hydrogen peroxide as a green oxidant, acid tetrabutylammonium salts of the γ-Keggin divanadium-substituted phosphotungstate [γ-PW10O38V2(μ-O)2]5- (I) as a catalyst, and MeCN as a solvent. The presence of the dioxovanadium core in the catalyst is crucial for the c...
A novel heterogeneous efficient procedure has been developed for the chemoselective synthesis of acylals (1,1-diacetates) under solvent-free conditions. A novel catalyst prepared by the sulfuric acid catalyzed copolymerization of p-toluenesulfonic acid and paraformaldehyde displays extremely high activities for the title reactions, affording average yields over 90% within several minutes. A com...
A solvent-free process was developed for the direct production of lactic acid from glucose in a mechanocatalytic process in the presence of Ba(OH)2, and a moderate lactic acid yield of 35.6% was obtained. Glucose conversion and lactic acid formation were favorable at higher catalyst/glucose mass ratios. However, at relatively lower catalyst/glucose mass ratios, they were greatly inhibited, and ...
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...
New supramolecular photocatalysts comprising an asymmetric bis-tridentate Ru(ii) complex that functions as a photosensitizer and a Ru(ii) carbonyl complex as the catalyst were designed. The complexes photocatalyzed the reduction of CO2 to CO or formic acid with high selectivity. The product distribution depended on the catalyst unit. CO and formic acid were the main products when using [Ru(BL)(...
The evaluation of the Kjeldahl digestion method was investigated by comparing measured values of total nitrogen, phosphorus and potassium using three salt and catalyst mixture in Standard Kjeldahl digestion method and Salicylic acid Modification method with certified values of plant material as well as comparison was made for determination of total nitrogen from steam distillation method verses...
there are no appreciable amounts of nickel resources in iran; therefore, secondary resources of this element are to be more considered in future. spent nickel catalysts that are used in various industrial processes are one of them. for example nickel catalyst that is used in hydrogenation of edible oil have large amounts of nickel and they are generally supported on porous materials like silica...
Pyrido[2,3-d]pyrimidine derivatives were synthesized regioselectivly in good to high yields by one-pot three-component condensation of 6-amino-2-(methylthio)pyrimidin-4(3H)-one, aromatic aldehydes and ethylcyanoacetate or meldrum's acid using 1,2-dimethyl-N-butanesulfonic acid imidazolium hydrogen sulfate ([DMBSI]HSO4) Brønsted-acidic ionic liquid as catalyst. Solvent-free mild reaction conditi...
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