Unit:
Κατεύθυνση Ομογενής ΚατάλυσηLibrary of the School of Science
Supervisors info:
Κωνσταντίνος Μεθενίτης, Αναπληρωτής Καθηγητής ΕΚΠΑ
Original Title:
Σύνθεση και χαρακτηρισμός νανοσωματιδίων Rh(0) σταθεροποιημένων σε υδατική φάση από τον πολυηλεκτρολύτη Πολύ-Ν-μεθακρυλοϋλο-L-μεθειονίνη. Εφαρμογή σε διφασική καταλυτική υδρογονωση
Translated title:
Synthesis and characterization of aqueous phase stabilized Rh (0) nanoparticles by the Poly-N-methacryloyl-L-methionine polyelectrolyte. Application in biphasic catalytic hydrogenation
Summary:
Synthesis and characterization of transition metal nanoparticles appear as highly interesting areas scientifically and commercially, due to certain properties, such as their role in catalysis. These properties depend on the size, the shape and the distribution of nanoparticles. Another important part is supporting nanoparticles by using water soluble polyelectrolytes in order to stabilize them against agglomeration and using biphasic systems so as to minimize the homogeneous catalysts defects, like recovering and recycling of the catalyst. The most serious problem concerning the use of homogeneous catalysts is recovering and recycling the catalyst but the solution comes from supporting nanoparticles on polyelectrolytes.For all of the aforementioned reasons, in this work we focus on the synthesis and characterization of Rh nanoparticles supported on poly-N-methacryloyl-L-methionine (PNMMeth). The precursor used for the synthesis are the complexesof Rh(III)-PNMMeth while characterization took place through UV-Vis and IR spectroscopies, and scanning electron microscopy (SEM). It is proven that the active catalyst is rhodium at its metallic state, Rh(0), and that it stays attached to the support even after the end of the reactions. The stabilized nanoparticles in aqueous solution proved to be active catalysts for the hydrogenation of cyclohexene in a biphasic system (water / organic phase) at temperatures 50oC and H2 pressure of 7 bar. The values of TON and TOF catalyst were calculated 150 and 1180 h-1. During the hydrogenation of 1-octen isomerisation to internal alkenes is also observed.
Main subject category:
Science
Keywords:
Nanoparticles, rhodium(0), hydrogenation, biphasic catalysis, polyelectrolytes
Number of index pages:
37
Number of references:
146
