RIANI P.

In the frame of energy transition and anthropogenic CO2 emission reduction, CO2 hydrogenation by using green hydrogen to produce Synthetic Natural Gas is considered as a promising option. Considering nickel low-cost and natural abundance, Ni-based catalysts are the most investigated and used materials for methanation reaction in the temperature...

Copper based catalysts are central for carrying dehydrogenation reactions. However, these materials are prone to deactivation by sintering and coke deposition. Irreversible sintering occurring during reaction (under the effect of temperature) is known to decrease both activity and selectivity, where the unwanted dehydration activity of the...

Two 20 wt.% Co/SiO2 catalysts have been prepared using silica gel as a support and cobalt acetate or nitrate as precursors. They were characterized before and after reaction using XRD, skeletal IR and DR-UV–vis-NIR spectroscopies and FE-SEM microscopy. Fresh catalysts are active in CO2 methanation at atmospheric pressure but rapidly deactivate...

20 wt.% cobalt catalysts supported on pure and 5 wt.% silica-containing alumina have been prepared and characterized by X-Ray Diffraction, IR and DR-UV-vis-NIR spectroscopies and Field-Emission Scanning Electron Microscopy (FE-SEM). The presence of a cobalt-containing surface spinel phase Co3-xAlxO4 and, for the silica-containing sample, of a...

Two 20 wt.% Co/SiO2 catalysts were prepared using silica gel as a support and cobalt acetate and nitrate as precursors, respectively. As a comparison unsupported amorphous cobalt nanoparticles (10–80 nm) were synthesized by decomposing cobalt carbonyl. They were characterized before and after reaction using XRD, IR spectroscopy in the range of...

A detailed critical analysis of the scientific literature data concerning catalysts for CO2 methanation based on nickel supported over oxides was performed. According to the obtained information, it seems that an ionic support is necessary to allow a good nickel dispersion to produce very small nickel metal particles. Such small metal particles...

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The waste materials available as sources of silicon and aluminum for producing porous materials like amorphous silicas, aluminas, amorphous silica-aluminas, and zeolites, to be used as catalyst and adsorbents, are briefly summarized. The procedures for preparing these materials from wastes are also taken into account. The limits of this...

BACKGROUND: Catalysts based on alumina-supported metal oxides are of crucial importance in the field of heterogeneous catalysis for several applications requiring tuning of surface acidity. RESULTS: In this work, the effects of K+, Ca2+ and La3+ cation doping have been evaluated on a well-characterized commercial gamma-Al2O3 through...

Background: Acetaldehyde is a main organic intermediate for manifold chemical products. In the near future, its production using renewable raw materials is rapidly becoming highly desirable. In this paper, investigations on pure and silica-supported molybdenum oxide (MoO3) as catalysts for the ethanol oxidative dehydrogenation process to...

The synthesis of magnetite (Fe 3 O 4 ) nanoparticles (NPs) and the functionalization by means of a silane derivative (3-mercaptopropyl) trimethoxysilane (MPTMS) as a way for heavy metal capture, i.e., Pb 2+ ions, has been investigated. A direct reaction between the active thiol organosilane molecule and the surface of the magnetite nanoparticle...

BACKGROUND: γ-Al2O3 and silica-doped aluminas are largely used supports for industrial catalysts. The addition of silica to alumina modifies its acid–base properties, also affecting its dispersion ability of supported species. In this paper, investigations on the silica doping effect in alumina-supported MoO3 catalysts, developed for the...

Commercial pure γ-Al2O3 and SiO2 (1−30 wt.%) doped γ-Al2O3 were characterized as acid catalysts in ethanol conversion and used as supports for NiO and MoO3. Supported catalysts were prepared by incipient wetness impregnation. All catalytic materials were characterized by BET, XRD, FE-SEM microscopy, UV–vis and IR spectroscopies. Pure and...

Al-Co-Cr-Fe-Ni alloys have been modeled by computational thermodynamics according to the CALPHAD approach using literature data and results of a few key experiments performed in this work. As a result, an Al-Co-Cr-Fe-Ni thermodynamic database has been developed, based on the thermodynamic assessments of all the binary and ternary subsystems and...

In order to valorize lignin wastes to produce useful aromatic compounds, the thermal degradation pyrolysis of Kraft lignin in the absence of catalysts has been investigated at 350, 450, and 550 °C. The high content of sulfur in the fresh sample led to the formation of S‐containing compounds in products whose evolution in the gas phase was...

CO2 methanation is a very promising technology for the production of alternative fuels with the simultaneous use of greenhouse gases. Therefore, intensive research is carried out on the optimization of catalysts with excellent properties for operation in the area of low temperatures. Here, we present research on a catalyst composed of 19 wt %...

Ni-based catalysts, 13.5 Ni wt.%, with enhanced thermal stability and catalytic performance for CO2 methanation have been synthesized with different La2O3 loadings. Catalysts have been extensively characterised by: XRD, IR, H2-TPR, IPA-TPD, UV–vis-NIR, FE-SEM and tested in CO2 methanation. SiO2 addition to Al2O3 support decreases the activity...