The Effect Of Catalyst Support On The Decomposition Of Methane To Hydrogen And Carbon.

Decomposition of methane into carbon and hydrogen over Cu/Ni supported catalysts was investigated. The catalytic activities and the lifetimes of the catalysts were studied. Cu/Ni supported on Ti02 showed high activity and long lifetime for the reaction. Transmission electron microscopy (TEM) studies revealed the relationship between the catalyst activity and the formation of the filamentous carbon over the catalyst after methane decomposition

Mechanism And Rate Limiting Step For The Catalytic Decomposition Of Methane To Hydrogen And Carbon Nanotube.

The main focus of this paper is to report a mechanism, a rate-limiting step, and a rate law consistent with experimental observation for the decomposition of methane to hydrogen and carbon nanotube over Ni/Mn based catalyst

The examination of NiO and CoOx catalysts supported on Al2O3 and SiO2 for carbon nanotubes production by catalytic chemical vapor deposition of methane.

The effects of catalyst components on the synthesis of carbon nanotubes (CNTs) are always the concern of many. The aimof this work is to examine the dependence of the morphology of CNTs formed on the nature of NiO and CoOx catalystssupported on Al2O3 and SiO2 at two different synthesis temperatures, i.e. 550oC and 700oC, respectively. Catalytic chemicalvapor deposition (CCVD) of methane was adopted for synthesizing the nanotubes materials. The developed catalysts werecharacterized by X-ray diffraction (XRD) and temperature programmed reduction (TPR). The morphology of the producedcarbon nanostructures was analyzed by transmission electron microscopy (TEM). The experimental result shows that CNTswere presence on the surfaces of most of the tested catalysts. The yield of the CNTs produced over these catalysts wascalculated. It was found that the yield decreased in the order of NiO/SiO2>CoOx/SiO2>CoOx/Al2O3>NiO/Al2O3 for thereaction at 550oC and in the order of NiO/SiO2>CoOx/Al2O3>CoOx/SiO2>NiO/Al2O3 at 700oC. The morphological analysisreveals that the structure of the CNTs depends upon the effects of metal-support interaction (MSI) and the synthesistemperature

A Novel Production Of Single-Walled Carbon Nanotubes And Hydrogen Via Single-Step Conversion Of Natural Gas.

A number of catalysts prepared from transition metals such as copper (Cu), iron (Fe), nickel (Ni), cobalt (Co) and manganese (Mn) on TiO2 support were tested for the decomposition of methane into hydrogen and carbon

The production of cox-free hydrogen and carbon nanofibers from direct catalytic decomposition of methane

Direct decomposition of methane was carried out using a fixed-bed reactor at 700oC for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiOM/ SiO2 catalysts (where M = AgO, CoO, CuO, FeO, MnOx, and MoO) in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO gave the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiO2 support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition has been determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8:2 (w/w) as the highest methane conversion was obtained over this catalyst

Synthesis and characterization of TiO2 coated multiwalled carbon nanotubes using a sol gel method

A considerable improvement in the quality of TiO 2 coatings on multiwalled carbon nanotubes (MWNTs) was obtained by introducing a three-step purification and functionalization process which combines oxidation in air followed by sulfuric acid refluxes and reoxidation in air before synmesis of the TiO 2 coating by the sol-gel method. A range of techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-rays (EDX), X-ray diffraction (XRD), Raman spectroscopy, and thermal gravimetric analysis (TGA) were applied to characterize TiO 2 coated MWNTs obtained by sol-gel. TEM results showed that the MWNTs were fully and homogeneously coated wim TiO 2 while SEM coupled with EDX confirmed me presence of a thick layer of TiO 2 coating the MWNTs. XRD and Raman spectroscopy results revealed that the crystalline structure of TiO 2 on the surface of MWNTs was anatase

The Effect of Catalyst Support on the Decomposition of Methane to Hydrogen and Carbon

Decomposition of methane into carbon and hydrogen over Cu/Ni supported catalysts was investigated. The catalytic activities and the lifetimes of the catalysts were studied. Cu/Ni supported on TiO2 showed high activity and long lifetime for the reaction. Transmission electron microscopy (TEM) studies revealed the relationship between the catalyst activity and the formation of the filamentous carbon over the catalyst after methane decomposition. While different types of filamentous carbon formed on the various Cu/Ni supported catalysts, an attractive carbon nanotubes was observed in the Cu/Ni supported on TiO2.  Key Words:  Methane decomposition, carbon nanotube, Cu/Ni supported catalysts

Structural and interaction properties of encapsulated Mno2 nanowires filled MWCNTs

Uniform encapsulated MnO2 nanowires were achieved within the cavity of multiwalled carbon nanotubes (MWCNTs). The Raman spectra revealed a charge-transfer shifts between the MnO2 particles and the inner tube of MWCNTs. Thin, uniform and continuous MnO2 was observed with a diameter of 9 nm