A general approach to fabricate fe3O4 nanoparticles decorated with Pd, Au, and Rh: Magnetically recoverable and reusable catalysts for Suzuki C-C cross-coupling reactions, hydrogenation, and sequential reactions

A facile strategy has been explored for loading noble metals onto the surface of ferrite nanoparticles with the assistance of phosphine-functionalized linkers. Palladium loading is shown to occur with participation of both the phosphine function and the surface hydroxyl groups. Hybrid nanoparticles containing simultaneously Pd and Au (or Rh) are obtained by successive loading of metals. Similarly, ferrite nanoparticles decorated with Pd, Au, and Rh have also been formed by using the same strategy. The catalytic properties of the new nanoparticles are evidenced in processes such as reduction of 4-nitrophenol or hydrogenation of styrene. Besides, the sequential process involving a cross-coupling reaction followed by reduction of 1-nitrobiphenyl has been successfully achieved by employing Pd/Au decorated nanoferrite particles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Postprint (published version

Remarkable carbon dioxide hydrogenation to ethanol on a palladium/iron oxide single-atom catalyst

The hydrogenation of CO2 into value-added chemicals is one of the most investigated methods to reduce CO2 emissions in the atmosphere and thereby contributes to a sustainable chemical industry. Whereas the catalytic hydrogenation of CO2 into methanol and synthetic hydrocarbons is well established, the effective and selective transformation of CO2 into higher alcohols is still challenging. Here, we show that Pd single atoms anchored on the surface of Fe3O4 are very active for the hydrogenation of CO2 to ethanol at 300 8C, even at atmospheric pressure. By comparing various Pd/MOx catalysts, we conclude that the metal–oxide interface has a strong influence on catalytic behavior.Postprint (author's final draft

Remarkable carbon dioxide hydrogenation to ethanol on a palladium/iron oxide single-atom catalyst

The hydrogenation of CO2 into value-added chemicals is one of the most investigated methods to reduce CO2 emissions in the atmosphere and thereby contributes to a sustainable chemical industry. Whereas the catalytic hydrogenation of CO2 into methanol and synthetic hydrocarbons is well established, the effective and selective transformation of CO2 into higher alcohols is still challenging. Here, we show that Pd single atoms anchored on the surface of Fe3O4 are very active for the hydrogenation of CO2 to ethanol at 300 8C, even at atmospheric pressure. By comparing various Pd/MOx catalysts, we conclude that the metal–oxide interface has a strong influence on catalytic behavior

Highly water-dispersible magnetite-supported Pd nanoparticles and single atoms as excellent catalysts for Suzuki and hydrogenation reactions

The molecule 4-(diphenylphosphino) benzoic acid (dpa) anchored on the surface of magnetite nanoparticles permits the easy capture of palladium ions that are deposited on the surface of the magnetite nanoparticles after reduction with NaBH4. Unexpectedly, a significant fraction of dpa is removed in this process. Samples of Fe(3)O(4)dpa@Pdx containing different Pd loadings (x = 0.1, 0.3, 0.5 and 1.0 wt%) were prepared, and their catalytic efficiency for the Suzuki C-C coupling reaction was studied. The best catalyst was Fe(3)O(4)[email protected], which gave the highest TOF published to date for the reaction of bromobenzene with phenylboronic acid in a mixture of ethanol/water (1/1). Interestingly, the same reaction carried out in water also produced excellent yields of the resulting C-C coupling product. The behaviour of other bromide aryl molecules was also investigated. The best catalytic results for the aqueous phase reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) were obtained using Fe(3)O(4)[email protected]. The presence of Pd SACs (single atom catalysts) seems to be responsible for this performance. In contrast, the same Fe(3)O(4)[email protected] catalyst is absolutely inactive for the hydrogenation of styrene in ethanol.Peer ReviewedPostprint (published version

Highly water-dispersible magnetite-supported Pd nanoparticles and single atoms as excellent catalysts for Suzuki and hydrogenation reactions

The molecule 4-(diphenylphosphino) benzoic acid (dpa) anchored on the surface of magnetite nanoparticles permits the easy capture of palladium ions that are deposited on the surface of the magnetite nanoparticles after reduction with NaBH4. Unexpectedly, a significant fraction of dpa is removed in this process. Samples of Fe(3)O(4)dpa@Pdx containing different Pd loadings (x = 0.1, 0.3, 0.5 and 1.0 wt%) were prepared, and their catalytic efficiency for the Suzuki C-C coupling reaction was studied. The best catalyst was Fe(3)O(4)[email protected], which gave the highest TOF published to date for the reaction of bromobenzene with phenylboronic acid in a mixture of ethanol/water (1/1). Interestingly, the same reaction carried out in water also produced excellent yields of the resulting C-C coupling product. The behaviour of other bromide aryl molecules was also investigated. The best catalytic results for the aqueous phase reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) were obtained using Fe(3)O(4)[email protected]. The presence of Pd SACs (single atom catalysts) seems to be responsible for this performance. In contrast, the same Fe(3)O(4)[email protected] catalyst is absolutely inactive for the hydrogenation of styrene in ethanol.Peer Reviewe

NH2- or PPh2-functionalized linkers for the immobilization of palladium on magnetite nanoparticles?

Immobilization of palladium on magnetite nanoparticles has been carried out with the assistance of two differently functionalized linkers containing phosphino- or amino-terminated groups. The linkers have been anchored to the magnetite surface by means of catechol, mercapto or carboxylate groups. The nature of the resulting Pd nanoparticles deposited has been examined by HAADF-STEM images and XPS electron spectroscopy. The efficiency of the two kinds of catalysts has been checked and compared for the Suzuki–Miyaura reaction, 4-nitrophenol reduction and styrene hydrogenation. The results evidence that the nanoparticles equipped with the phosphino fragment are better catalysts than those functionalized with the amino group and, in some processes, they are among the most active catalysts reported in the literature.Postprint (published version

NH2- or PPh2-functionalized linkers for the immobilization of palladium on magnetite nanoparticles?

Immobilization of palladium on magnetite nanoparticles has been carried out with the assistance of two differently functionalized linkers containing phosphino- or amino-terminated groups. The linkers have been anchored to the magnetite surface by means of catechol, mercapto or carboxylate groups. The nature of the resulting Pd nanoparticles deposited has been examined by HAADF-STEM images and XPS electron spectroscopy. The efficiency of the two kinds of catalysts has been checked and compared for the Suzuki–Miyaura reaction, 4-nitrophenol reduction and styrene hydrogenation. The results evidence that the nanoparticles equipped with the phosphino fragment are better catalysts than those functionalized with the amino group and, in some processes, they are among the most active catalysts reported in the literature