ChemInform Abstract: Synergistic Promoting Effect of Ball Milling and KF-Alumina Support for the Green Synthesis of Benzothiazinones.

Abstract In this work, a novel C(sp3)–C(sp2) cross-dehydrogenative-coupling method is developed to react benzoxazin-2-one derivatives with various indoles. As a result, combined use of ball milling and Fe(ii) catalysis leads to rapid coupling of 1,4-benzoxazinones with derivatives of indole. Under the conditions, derivatives of 1 couple with various indoles at room temperature to produce good yields of the desired compounds within 0.5–2 h time period. Thus, derivatives of both starting materials couple smoothly under relatively mild conditions to give good yields of 3.

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Facile and scalable green synthesis of N-doped graphene/CNTs nanocomposites via ball milling

Ain Shams Engineering Journal ◽

10.1016/j.asej.2020.04.011 ◽

2020 ◽

Author(s):

A.N. Fouda ◽

El Shazly M. Duraia ◽

Ali A. Almaqwashi

Keyword(s):

Green Synthesis ◽

Ball Milling ◽

Doped Graphene

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The promoting effect of cesium on structure and morphology of silver catalysts

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652004000100003 ◽

2004 ◽

Vol 76 (1) ◽

pp. 19-27 ◽

Cited By ~ 4

Author(s):

Marta C. N. A. Carvalho ◽

Carlos A. Perez ◽

Renata A. Simão ◽

Fabio B. Passos ◽

Martin Schmal

Keyword(s):

Atomic Force Microscopy ◽

Supported Catalysts ◽

Metallic Silver ◽

X Ray Diffraction ◽

Promoting Effect ◽

Alumina Support ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Microscopy Techniques

Silver supported catalysts on alpha-alumina were prepared and characterized by Brunauer-Emmet-Teller equations, scanning electronic microscopy, X-ray diffraction and atomic force microscopy techniques. Results show that these are powerful techniques for the determination of texture, morphology and surface properties. It has been shown that the addition of Cs in the Ag/Al2O3 catalyst increased the dispersion of silver with the formation of small silver particles over a thin silver film already formed over the alumina support. It is important to stress that atomic force microscopy measurements are significant to observe the film and the dispersion of Ag and, on the contrary, X-ray photoelectronic spectroscopy did not, however, it allows to the conclusion that undistinguishable silver, either as metallic or oxidation state, are present at the surface. X-ray diffraction results confirm predominantly metallic silver.

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Oxidative Dehydrogenation of Propane over Vanadium Catalyst Supported on Alkali-Modifiedx-Al2O3

Chemical Science International Journal ◽

10.9734/csji/2021/v30i930250 ◽

2021 ◽

pp. 1-15

Author(s):

Vinicius M. Crivelaro ◽

Sayuri Okamoto ◽

Gilberto G. Cortez

Keyword(s):

Oxidative Dehydrogenation ◽

Alkali Metals ◽

Large Fraction ◽

Molar Fraction ◽

Propane Conversion ◽

Promoting Effect ◽

Alumina Support ◽

Molar Ratios ◽

Propane Odh ◽

Acidic Sites

The propane oxidative dehydrogenation (ODH) reaction has been considered as an alternative method for propene production owing to its exothermic nature, which renders it environmentally friendly. The use of alkaline promoters for supported V catalysts can increase propene selectivity and partially inhibit the formation of CO and CO2. Our goal was to evaluate the promoting effect of K and Na and the support effect using gibbsite as precursor for the propane ODH reaction. Catalysts were prepared via co-impregnation of V and alkali metals on a previously prepared alumina support and were characterized using N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, and isopropanol decomposition tests to evaluate their acid-base properties. The activity of the synthesized catalysts for the propane ODH reaction was evaluated at the O2:C3H8:He molar ratios of 5:2:4, 6:1:4, and 4:3:4. The addition of alkali metals to the V catalysts increased propane conversion and propene selectivity; moreover, both parameters increased with increasing molar fraction of O2 in the reactants. K doping increased the propene selectivity of the doped catalysts, because it inhibited a large fraction of catalytic surface acidic sites. A high molar fraction of O2 in the reactants facilitated the regeneration of the catalyst, whereas a high reoxidation rate improved catalytic activity and propene selectivity.

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