نتایج جستجو برای: acid catalyst
تعداد نتایج: 784490 فیلتر نتایج به سال:
The direct formic acid fuel cell is an emerging energy conversion device for which palladium is considered as the state-of-the-art anode catalyst. In this communication, we show that the activity and stability of palladium for formic acid oxidation can be significantly enhanced using nickel phosphide (Ni(2)P) nanoparticles as a cocatalyst. X-ray photoelectron spectroscopy (XPS) reveals a strong...
[b(oh)3]0.78[b(oh)2(oso3h)]0.22 or (bsa) was simply prepared by addition of chlorosulfonic acid to commercial boric acid at room temperature. this cheap and green solid acid was used as an efficient catalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.
Present process of transesterification faces various challenges. The most challenging is to obtain high conversion rate when using high free fatty acid (FFA) feedstock. The aim of this study is to investigate transesterification process of rubber seed oil (RSO) through direct-ultrasonic irradiation (UI) with addition of waste material based heterogeneous catalyst. The waste material based heter...
Kanemite was readily prepared and used as solid base catalyst for transesterification of sunflower oil to fatty acid methyl ester (FAME). The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption and field emission scanning electron microscopy (FESEM) techniques. Central Composite Design (CCD) coupled with Response Surfac...
sulfonated polystyrene/montmorillonite nanocomposite (ommt/ps-so3h) was prepared and used as a novel, efficient and inexpensive heterogeneous acid catalyst in the one-pot reaction three-component mannich reaction of ketones, aromatic aldehydes and amines under solvent-free conditions. the catalyst was characterized by xrd, sem, tg, bet and ft-ir techniques. this method has advantages of high yi...
Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...
bimetallic pt-v supported by gamma-alumina is used to observe the changes of nheptanewhen passed over this catalyst. the pt concentration was kept constant at0.1wt% while the concentration of the vanadium was 0.5wt%. the activity andselectivity of catalyst have been determined under conditions at 450-500 degreescentigrade and 15-30 attn. the experimental results show that the addition of second...
An efficient method for the synthesis of mono and bulky 1,8-dioxooctahydroxanthenes was developed by the reaction of dimedone or 1,3-cyclohexadione and aldehydes or some bisaldehydes in the presence of polyvinylpolypyrrolidone supported oxalic acid (PVPP-OXA) as a new polymeric catalyst in ethanol at room temperature. Polyvinylpolypyrrolidone supported oxalic acid was characterized by FT-IR, an...
In this study, esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, Oleic acid) with ethanol was investigated by ZnO, Al2O3-ZnO mixed oxide and phosphotungestic acid (10 %wt) immobilized on the Al2O3-ZnO mixed oxide. The heterogeneous catalysts were characterized by XRD, BET, FE-SEM and EDX techniques. Optimum yield was achieved by using 10% HPW/Al2O3-ZnO as the be...
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