Preparation of Pt@Fe₂O₃ Nanowires and their Catalysis of Selective Oxidation of Olefins and Alcohols

Abstract

Iron oxide coated platinum nanowires (Pt@Fe(2)O(3)NWs) with a diameter of 2.8 nm have been prepared by the oxygen oxidation of FePt NWs in oleylamine. These "cable"-like NWs were characterised by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and X-ray absorption fine structure analysis. These Pt@Fe(2)O(3) NWs were used as "non-support" heterogeneous catalysts in oxidation of olefins and alcohols. The results revealed that it is an active and highly selective catalyst. Styrene derivatives were tested with molecular oxygen as the sole oxidant, with benzaldehyde successfully obtained from styrene in an absolute yield of 31%, whereas the use of tert-butyl hydroperoxide as the sole oxidant in the oxidation of alcohols led to yields of more than 80% of the corresponding ketone or aldehyde. This unsupported catalyst was found to be more active (TOF=96.5 h(-1)) than other reported Fe(2)O(3) nanoparticle catalysts and could be recycled multiple times without any notable decrease in activity. Our findings will extend the use of such nanomaterial catalysts to new catalytic systems.

Selective Photocatalytic Oxidation of Aniline to Nitrosobenzene by Pt Nanoparticles Supported on TiO2 under Visible Light Irradiation

“…In contrast, the Pt 2 /P25 catalyst produces nitrosobenzene (9.7 μmol) with a minor amount of azobenzene (2.5 μmol). Although Pt nanoparticles exhibit catalytic activity for aerobic oxidation even under the dark condition, 34,35 the Pt 2 /P25 catalyst, when reacted under the dark condition, gave only a minor amount of products. An increase in temperature enhances the reaction even under the dark condition, but azobenzene is produced as a main product because of the condensation of aniline with the formed nitrosobenzene enhanced at higher temperatures.…”

Directing Reaction Pathways through Controlled Reactant Binding at Pd–TiO2 Interfaces

“…[4][5][6][7][8] Thei mportance of interfacial sites in catalysis suggests that catalyst design should emphasize novel methods for tailoring these interfaces that go beyond using the oxide as as imple catalyst carrier. While encapsulated structures have been applied to enhance the stability of metal NPs [11][12][13][14] or improve the selectivity and/or activity for selective oxidation, [15][16][17] hydrogenation, [18][19][20] and decarbonylation, [21] HDO provides an important probe reaction for testing their utility for reactions that occur at metal/oxide interfaces.M oreover,t he unique geometry of the sites in an encapsulated structure could result in an ew way to control interfacial properties via biasing the reactant binding orientations.F or aromatic alcohols,flat-lying adsorbates are prone to decarbonylation and ring hydrogenation while upright adsorption geometries favor HDO. While encapsulated structures have been applied to enhance the stability of metal NPs [11][12][13][14] or improve the selectivity and/or activity for selective oxidation, [15][16][17] hydrogenation, [18][19][20] and decarbonylation, [21] HDO provides an important probe reaction for testing their utility for reactions that occur at metal/oxide interfaces.M oreover,t he unique geometry of the sites in an encapsulated structure could result in an ew way to control interfacial properties via biasing the reactant binding orientations.F or aromatic alcohols,flat-lying adsorbates are prone to decarbonylation and ring hydrogenation while upright adsorption geometries favor HDO.…”

“…[9,10] Ap romising approach is to employ inverted systems in which the metal oxide is deposited as afilm onto the metal nanoparticles (NPs). While encapsulated structures have been applied to enhance the stability of metal NPs [11][12][13][14] or improve the selectivity and/or activity for selective oxidation, [15][16][17] hydrogenation, [18][19][20] and decarbonylation, [21] HDO provides an important probe reaction for testing their utility for reactions that occur at metal/oxide interfaces.M oreover,t he unique geometry of the sites in an encapsulated structure could result in an ew way to control interfacial properties via biasing the reactant binding orientations.F or aromatic alcohols,flat-lying adsorbates are prone to decarbonylation and ring hydrogenation while upright adsorption geometries favor HDO. [22][23][24][25][26][27][28] Here,w er eport on am ethod for controlling the encapsulation of Pd NPs with nanoporous TiO 2 to produce interfacial sites where accessible conformations of aromatics are restricted.…”

Electrochemical Simultaneous Sensing of Melatonin, Dopamine and Acetaminophen at Platinum Doped and Decorated Alpha Iron Oxide

“…Further, association of these metal nanoparticles on the amorphous metal oxide as an outer shell promotes the catalytic activity of the core oxide through tuning the electronic structure of the core and coordination of the outer shell. In this context, it is reported that one pot synthesized core shell structured Pt@Fe 2 O 3 showed enhanced catalysis . Noble metal functionalized iron oxide core shells are reported for catalytic oxidations of CO, water gas shift reactions, , and organic reactions .…”