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Liquid-phase hydrogenation of unsaturated aldehydes: enhancing selectivity of M...

The integration of nanotechnology into bioassays is having a great impact with the development of new nanostructures, nanodevices, nanomaterials or, in general, nanoparticles (NPs), such as nanoshells, nanowires, nanotubes and nanobarcodes, of a variety of shapes, sizes and composition [1-4]. These NPs, which exhibit new properties that are not shown by the bulk matter, are being considered as an alternative to...

Carbon xerogel supported noble metal catalysts for fine chemical applications

Carbon xerogel, a mesoporous material, was produced by polycondensation of resorcinol and formaldehyde. A concentrated nitric acid solution was subsequently used to introduce high amounts of oxygenated groups on the surface. The carbon xerogel served as a support for Pt, Ir and Ru monometallic catalysts by using organometallic precursors. The catalysts were tested in the liquid-phase selective hydrogenation of ...

High temperature activation of noble metal catalysts supported on carbon multi-...

Selective catalytic hydrogenation of α,β-unsaturated aldehydes represents today an important route in the industrial preparation of fine chemicals. Heterogeneous catalysts are normally less selective than the homogeneous, but easier to handle. Therefore, there is still room for improvement especially regarding catalyst selectivity to the unsaturated alcohol. Our work shows that the surface chemistry also plays ...

Carbon xerogel as catalytic support for noble metal based selective hydrogenati...

Nitric acid treated carbon xerogel was used as support to prepare Pt, Ir and Ru monometallic catalysts. The introduction of oxygen surface groups was important to increase metal dispersion but proved to limit selectivity to cinnamyl alcohol during the hydrogenation of cinnamaldehyde. After an activation treatment to remove unwanted surface groups, Pt catalysts exhibited the highest selectivity, 73%, followed by...

Carbon supported noble metal catalysts prepared by photochemical deposition

Photochemical deposition of noble metals in different supports is gaining importance because of its simplicity and advantages. Its main advantage is the ability of spreading very effectively the metal throughout the support, thus leading to very high dispersions, resulting in higher molecular control, with a positive effect on both activity and selectivity. This type of catalysts is important for industrial pre...

Carbon nanotubes supported catalysts for selective hydrogenations of unsaturate...

Photochemical deposition of Platinum over MWNT: making catalysts for selective ...

In the present study, the photochemical deposition method was compared against the usual incipient wetness procedure in the preparation of supported Pt catalysts. Particular attention was given to parameters such as nature of the support (multiwalled carbon nanotubes, MWNT vs. titanium dioxide, TiO2) and reduction temperature. Supported 1% wt Pt catalysts treated in hydrogen at 773K showed improved activity and...

Carbon supported platinum catalysts for catalytic wet air oxidation of refracto...

Carbon supported platinum (1% wt) catalysts were prepared by the incipient wetness impregnation method and by organometallic chemical vapor deposition. Catalyst characterization was carried out by means of adsorption and thermogravimetric techniques, and by electron microscopy. The catalyst with higher metal dispersion was produced by incipient wetness impregnation. The catalysts were tested in the catalytic we...

Supported platinum catalysts prepared by photochemical deposition

The challenges of treating high strength wastewaters: CWAO using MWNT supported...

High strength wastewaters containing aromatic compounds are normally not efficiently treated by conventional methods, including the common biological treatment. In these cases a more sophisticated approach is necessary to attain the desired levels of purification. Catalytic wet air oxidation (CWAO) using carbon based catalysts is employed worldwide as effective pre-treatment of effluents with these characterist...