Seed-mediated synthesis of bimetallic ruthenium–platinum nanoparticles efficient in cinnamaldehyde selective hydrogenation

Abstract

Core-shell RuPt (Ru core-Pt shell) and PtRu (Pt core-Ru shell) nanoparticles were prepared by decomposing in a two-step procedure a ruthenium ([Ru(COD)(COT)] (COD = 1,5-cyclooctadiene, COT = 1,3,5-cyclooctatriene)) and a platinum complex ([Pt2(dba)3] (dba = dibenzylideneacetone) or [Pt(CH3)2(COD)]) in the presence of 4-(3-phenylpropyl)pyridine (PPP) as a stabilizer and using different Ru/Pt ratios. The data obtained from a combination of several analyses (TEM, HRTEM, WAXS and IR) indicate that the so-obtained nanoparticles present a core-shell structure. The catalytic performances of these bimetallic nanoparticles for the selective hydrogenation of trans-cinnamaldehyde were investigated, which provided interesting results as well as useful information to elucidate their structure and composition. Indeed, the catalytic results evidence that: (1) the combination of both metals led in some cases to a synergistic effect on the selectivity of the reaction, and (2) the structure and the composition affected the selectivity of the reaction.

Synthesis and structure of ruthenium-fullerides

“…We assigned this broad signal, which increases in intensity with the number of Ru NPs present on the sample, to terminal CO adsorbed on the Ru NPs surface as it usually appears in the region of 1970-2000 cm À1 . 79,80 For higher Ru-C 60 ratios, the ATR-IR signal intensity was too low for interpretation.…”

Catalysis with Colloidal Ruthenium Nanoparticles

“…101 It is not surprising that Ru NPs have found applications as catalysts for a large panel of reduction reactions, mainly C=C and C=O bonds, in a broad range of reaction conditions. Ru NPs used as catalysts in reduction reactions are synthesised by one of the methodologies described above using a large variety of stabilizing agents, such as polymers, [73][74][102][103][104][105][106][107][108][109][110][111] phosphines, [112][113][114][115][116] N-donor ligands, 50,[117][118] ILs, [83][84][119][120][121][122][123][124][125][126][127][128][129][130][131] NHC, 96,[132][133][134][135][136][137][138][139] alkynes, 140 chitin,…”

Organometallic Metal Nanoparticles for Catalysis

“…Interestingly, these RuPt/dppb NPs were more active towards arene hydrogenation even after CO poisoning, thus pointing to the interest of preparing bimetallic species. In the same line, more information about the composition of RuPt catalysts could be ascertained by analysing the results obtained in the selective hydrogenation of trans-cinnamaldehyde, as detailed below [32].…”

“…Moreover, preformed Ru NPs and Pt NPs were used as seeds for the preparation of core-shell RuPt and PtRu NPs, by a two step procedure. Several metal Ru/Pt ratios were used and 4-(3-phenylpropyl)pyridine (PPP) was introduced as capping ligand [32]. Besides interesting results, the implementation of these bimetallic RuPt NPs as catalysts in the hydrogenation of trans-cinnamaldehyde greatly contributed to finely determine the composition and metal distribution in these NPs and complementarily to usual chracterization techniques (IRFT, NMR, TEM, WAXS).…”