The design and green synthesis of new nanomaterials and their application in catalysis

Funder

Organizational Unit

Publications

Mechanochemical preparation of Pd and Pt composites for Suzuki-Miyaura reactions

Publication . Soliman, Mohamed M. A.; Da Costa Ribeiro, Ana Paula; Saraiva, Marta S.; Alegria, Elisabete; Pombeiro, Armando

The application of green, simple, time- and energy-saving mechanochemical ball-milling procedures for the dispersion of palladium and platinum salts or oxides over MWCNTs (multi-walled carbon nanotubes) and activated carbon is reported. Carbon nanotubes have exceptional properties (e.g. high mechanical strength and surface areas) which make them promising materials for various applications. In this respect, we apply dispersed palladium and platinum composites [1-2] as catalysts in the Suzuki-Miyaura reactions. Both the preparation of the dispersed materials and the catalytic Suzuki-Miyaura reactions were performed by ball-milling and the results are discussed.

2017-06Conference object

Restricted access

Ultrasound and radiation-induced catalytic oxidation of 1-phenylethanol to acetophenone with iron-containing particulate catalysts

Publication . Soliman, Mohamed Mostafa Aboelhassan; Kopylovich, Maximilian N.; Alegria, Elisabete; Da Costa Ribeiro, Ana Paula; Ferraria, Ana Maria; Rego, Ana; Correia, Luís M. M.; Saraiva, Marta S.; Pombeiro, Armando

Iron-containingparticulatecatalystsof0.1–1 µmsizewerepreparedbywetandball-milling procedures from common salts and characterized by FTIR, TGA, UV-Vis, PXRD, FEG-SEM, and XPS analyses. It was found that when the wet method was used, semi-spherical magnetic nanoparticles were formed, whereas the mechanochemical method resulted in the formation of nonmagnetic microscale needles and rectangles. Catalytic activity of the prepared materials in the oxidation of 1-phenylethanol to acetophenone was assessed under conventional heating, microwave (MW) irradiation, ultrasound (US), and oscillating magnetic ﬁeld of high frequency (induction heating). In general, the catalysts obtained by wet methods exhibit lower activities, whereas the materials prepared by ball milling aﬀord better acetophenone yields (up to 83%). A signiﬁcant increase in yield (up to 4 times) was observed under the induction heating if compared to conventional heating. The study demonstrated that MW, US irradiations, and induction heating may have great potential as alternative ways to activate the catalytic system for alcohol oxidation. The possibility of the synthesized material to be magnetically recoverable has been also veriﬁed.

2020-02-01Journal article

Open access