IR spectroscopic insights into the coking-resistance effect of potassium on nickel-based catalyst during dry reforming of methane

Dry reforming of methane (DRM) is an effective catalytic route for transforming CO2 and CH4 into valuable syngas and thus potentially attractive for mitigating the emission of environmental harmful gases. Therefore, it is crucial to develop rationally Ni-based catalysts highly resistant to coking and sintering. In this scenario, the addition of small amounts of potassium to nickel…

Fructose dehydration reaction over functionalized nanographitic catalysts in MIBK/H2O biphasic system

A series of functionalized nanographitic carbons is prepared, characterized and tested in fructose dehydration reaction to 5-hydroxymethylfurfural. The functionalization treatment was selected to introduce various Bro?nsted acid sites and to modify the textural and catalytic properties of the initial carbon material. Within the series, the sulfonated carbons present the most interesting catalytic behavior resulting in…

Form Birefringence in Resonant Transducers for the Selective Monitoring of VOCs under Ambient Conditions

In this work, we have developed a new kind of nanocolumnar birefringent Bragg microcavity (BBM) that, tailored by oblique angle deposition, behaves as a selective transducer of volatile organic compounds (VOCs). Unlike the atomic lattice origin of birefringence in anisotropic single crystals, in the BBM, it stems from an anisotropic self-organization at the nanoscale of…

Enhancing the electrical conductivity of in-situ reduced graphene oxide-zirconia composites through the control of the processing routine

Graphene oxide (GO) was mixed with 3 mol% yttria tetragonal zirconia polycrystal (3YTZP) using two powder processing routines: a colloidal method in an aqueous solution and a combination of ultrasonication with highenergy planetary ball milling in wet conditions. Highly densified 3YTZP composites with reduced GO (rGO) were consolidated by Spark Plasma Sintering. The in-situ reduction…

Organophilization of acid and thermal treated sepiolite for its application in BTEX adsorption from aqueous solutions

Acid and thermal treated sepiolite was organophilized by cationic exchange with several alkylammonium cations (octylammonium, hexadecylammonium, tetradecyltrimethylammonium, and hexadecyltrimethylammonium). The adsorption capacity of BTEX from aqueous solutions was evaluated through the adsorption isotherms performed in batch. The results were analysed using three isotherm models: Freundlich, Langmuir and Dubinin-Radushkevich (D-R model). The behaviour of adsorption isotherm…

Rietveld Refinement, mu-Raman, X-ray Photoelectron, and Mossbauer Studies of Metal Oxide-Nanoparticles Growth on Multiwall Carbon Nanotubes and Graphene Oxide

Applying a modified coprecipitation method, maghemite and anatase nanoparticles embedded in graphene oxide and multiwall carbon nanotube frameworks were prepared, and a detailed structural characterization is presented. Transmission electron images have revealed that the multiwall carbon nanotubes and graphene oxide act as substrates to reduce the nanoparticle agglomeration with narrow sizes of ca. 9-20 nm,…