Steam Reforming of Glycerol over Ni Supported Alumina Xerogel for Hydrogen Production

AbstractMomentous amount of glycerol is produced as a by-product during bio-diesel production by the transesterification of vegetable oils, which are available at low cost in large supply from renewable raw materials. As hydrogen is a clean energy carrier, conversion of glycerol to hydrogen is one among the most attractive ways to make use of glycerol. In this study, the catalytic production of hydrogen by steam reforming of glycerol has been experimentally performed in a fixed-bed reactor. The performance of this process was evaluated over 10wt% Ni supported alumina xerogel catalysts. Ni is impregnated over alumina xerogel which was pretreated at different temperatures of 700°C, 800°C, 900°C and 1000°C. For a comparative purpose, the steam reforming experiments were conducted under same operating conditions, i.e., reaction temperature of 600°C, atmospheric pressure and 1:6 glycerol to water molar ratio where we are getting 100% glycerol conversion in all the runs. The results showed that the hydrogen production increased with the increase in the treatment temperature of the support. The highest amount of hydrogen produced was attained over 10wt% Ni doped alumina xerogel pretreated at 1000°C. The catalytic enhancement over the best catalyst system is due to the thermal stability of the support which is treated at highest temperature. Sol gel method of preparation is implemented in the support development and different catalyst systems used in the reforming process were characterized using X-ray powder diffraction, BET surface area and SEM analysis

The Activity of Ni-Based Catalysts on Steam Reforming of Glycerol for Hydrogen Production

Glycerol, the readily available bio renewable material, is effectively utilized for hydrogen production by a steam reforming reaction. The experiments were carried out in a continuous flow fixed-bed reactor over Nickel supported alumina catalysts under atmospheric pressure at 600°C and three hours reaction time. 5%wt Ni was loaded over γ-Al2O3 and effect of promoter metals such as Fe and Co over Ni/γ-Al2O3 catalytic systems were evaluated. The catalysts were characterized by BET surface area, XRD and SEM techniques. The activity results showed that the addition of Co enhanced the catalyst performance. The catalysts exhibited a good activity and selectivity to hydrogen

Au/TiO 2

Nanogold doped TiO2 catalysts are synthesized, and their application in the photodegradation of dye pollutants is studied. The materials are characterized using different analytical techniques such as X-ray diffraction, transmission electron microscopy, UV-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the strong interaction between the metallic gold nanoparticles and the anatase TiO2 support. Au doped systems showed very good photoactivity in the degradation of dye pollutants under UV irradiation as well as in sunlight. A simple mechanism is proposed for explaining the excellent photoactivity of the systems. The reusability studies of the photocatalysts exhibited more than 98% degradation of the dye even after 10 repeated cycles

Synthesis of polyaniline-montmorillonite nanocomposites using H2O2 as the oxidant

Polyaniline montmorillonite nanocomposite was prepared using H2O2 as the oxidant. The catalytic environment of montmorillonite favours polymerization. Intercalation and composite formation was proven from various techniques such as XRD, FTIR, DRS and thermal analysis. XRD patterns give the dimension of the intercalated PANI, from the shift of 2θ values, which is in the nano range. FTIR showed that PANI composite formation occured without affecting the basic clay layer structure. Thus the successful development of an alternative cheap route for polyaniline–montmorillonite nanocomposite was well established

Green Preparation of Fe₂O₃ Doped Gum Acacia Derived Porous Carbon/Graphene Ternary Nanocomposite as a Supercapacitor Electrode

The extended applications of the supercapacitor are possible with the attainment of a wide potential window since then it can exhibit high energy density too. Thus, organic electrolytes are more feasible in supercapacitors due to the accessibility of wide potential windows and the resultant higher storage/release of energy. A high-performance supercapacitor electrode material is prepared here via an eco-friendly procedure using a combination of Fe2O3, gum acacia derived porous carbon, and a ball-mill synthesized graphene for the first time. The synergistic action of the metal oxide and the carbon materials provided excellent specific capacitance values to the ternary nanocomposite. An appreciable specific capacitance of 433 F/g has been displayed by the composite coated glassy carbon electrode at a current density of 6 A/g in tetraethylammonium tetrafluoroborate—acetonitrile electrolyte at a wide potential window of 2.5 V. The material showed outstanding cyclic stability of 109% of the initial specific capacitance after 5000 repeated cycles

Solvent free one pot synthesis of amidoalkyl naphthols over phosphotungstic acid

Montmorillonite KSF clay was effectively modified by the encapsulation of phosphotungstic acid into the clay layers via sonication followed by incipient wet impregnation method. The prepared catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The catalytic activities of the prepared systems were investigated in the solvent free synthesis of amidoalkyl naphthols by the multicomponent one-pot condensation of an aldehyde, β-naphthol and an amide or urea. Excellent yield, shorter reaction time, easy work-up, and reusability of the catalyst are the main attractions of this green procedure

Au/TiO 2 Reusable Photocatalysts for Dye Degradation

Nanogold doped TiO 2 catalysts are synthesized, and their application in the photodegradation of dye pollutants is studied. The materials are characterized using different analytical techniques such as X-ray diffraction, transmission electron microscopy, UVvisible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the strong interaction between the metallic gold nanoparticles and the anatase TiO 2 support. Au doped systems showed very good photoactivity in the degradation of dye pollutants under UV irradiation as well as in sunlight. A simple mechanism is proposed for explaining the excellent photoactivity of the systems. The reusability studies of the photocatalysts exhibited more than 98% degradation of the dye even after 10 repeated cycles

An Enthusiastic Glance in to the Visible Responsive Photocatalysts for Energy Production and Pollutant Removal, with Special Emphasis on Titania

As a consequence of the rapid growth of industry, major problems are created related to energy and environment. Sunlight being one of the most potential alternative source of energy, the development of efficient solar-energy storage systems is an important subject in the fields of science and technology. Here we have reviewed and summarized some of the recent reports on visible responsive photocatalysts. In this review, the influence of various metal oxide photocatalysts on energy production and pollutant removal are presented with special emphasis on titania based photocatalysts. The photoactivity of titania for various pollutant degradation, modified titania (TiO2) systems, their physical and chemical characteristics, and so forth, are described in detail at this juncture. Different methods used to enhance the visible light absorption of TiO2, like doping with metals and nonmetals, coupling with other metal oxides, and so forth, have been discussed. Various applications of photocatalysts including photocatalytic treatment of waste water, pesticide degradation and water splitting to produce hydrogen are summarized. The development of photocatalysts that function under visible light for the efficient utilization of sunlight is an area of current interest and thus the different methods of preparation for the visible active photocatalysts are also explored