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Achieving high selectivity is one of the major challenges in heterogeneous catalysis, being carbon materials universally employed as catalysts support due to their so-called “inert” nature. However, due to the complexity of its intrinsic characteristics, there are still several factors to bear in mind when selecting the appropriate carbon support. In this work we demonstrate that the remaining sulfur...
In this work we report a simple procedure for synthesis of Cu and Pd catalysts supported on high surface area graphite (HSAG) by wetness impregnation technique, and further generation of metal nanoparticles using NaBH4 as reducing agent. The catalysts have been tested in the reduction of 4-nitrophenol to 4-aminophenol, at room temperature, in presence of NaBH4 as hydrogen source. Both Cu and Pd catalysts...
Various carbon materials differing in surface area, nanostructure and grade of graphitization were used to support ruthenium catalysts for the steam reforming of glycerol. Activity measurements performed in a traditional reactor indicated that the reaction is structure sensitive and the initial activity for hydrogen production of the catalysts decreases with decreasing Ru particle size. Among the...
The interaction of organic chemicals with the surface of carbon nanotubes (CNTs) has been studied by immersion calorimetry revealing new information about the unique CNT surface structures. The curvature of the graphene sheets of in the CNTs increases the adsorption strength of aromatic compounds compared to flat graphite surfaces. For a given CNT, the adsorption affinity of a non-polar aromatic molecule...
Graphene oxide nano-platelets were produced from helical-ribbon carbon nanofibers by oxidation with KMnO 4 /H 2 SO 4 and further exfoliation by ultrasonication. The KMnO 4 to carbon nanofiber ratio is 1:1. TEM and AFM were used to characterize the samples. TEM shows individual nanocrystals with straight edges and SAED yields a hexagonal spot pattern arrangement, attributed...
Ru catalysts were supported on two different carbon materials, multiwall carbon nanotubes and bamboo-like carbon nanotubes doped with nitrogen, which were synthesized by catalytic chemical vapour deposition of C 2 H 2 /H 2 /N 2 or C 2 H 2 /NH 3 /H 2 /N 2 , respectively, over Fe/SiO 2 catalyst. All the carbon supports and/or...
Iron acetylacetonate complexes anchored on oxidized carbon nanofibres (CNFs) were prepared by a three steps procedure: (i) oxidation of commercial CNFs by treatment with HNO 3 , (ii) synthesis of acetylacetonate (acac) functional groups on the oxidized CNFs surfaces (acac/CNFs) and (iii) iron ions complexation on the acac sites of the CNFs (Fe-acac/CNFs). The surface groups exposed on the...
Ru catalysts supported on three types of graphite nanofiber materials, stacked-cup (PR24-HHT), platelet (CNF-P) and bamboo-like (CNF-B), have been synthesized and characterized by HRTEM and calorimetry of CO adsorption. The influence of the support nanostructure on their catalytic performance in the selective hydrogenation of paracetamol was also studied. An inverse correlation between the heats of...
Temperature-programmed reduction (TPR) and CO adsorption microcalorimetry along with the catalytic behaviour in the n-butane/H 2 test reaction were performed in order to determine the specific interactions of Ru nanoparticles supported on different carbon materials. Aspects such as the porous structure and surface chemistry (presence and elimination of surface oxygen functional groups) of...
The copper-catalysed reduction of NO with carbon has been studied over copper-loaded carbon materials (graphites and activated carbon). Characterization of the different preparations has been carried out by X-ray diffraction, temperature-programmed reduction in hydrogen and surface reaction of NO. The copper loading, the nature of the copper phase, the presence of functional groups on the surface...
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