Platinum was electrodeposited in a slurry solution of CeO2 and Vulcan XC-72R to produce Pt/CeO2−x/Vulcan XC-72R catalysts by using the Rotating Disk Slurry Electrodeposition (RoDSE) Technique. The activity of the catalysts was measured towards methanol and ethanol oxidation reactions in alkaline conditions by cyclic voltammetry and chronoamperometry. The electrochemical results were compared to those obtained on commercial catalysts. Pt/CeO2−x/Vulcan XC-72R (with ∼ 26 wt% Pt) catalyst was the most active for both alcohol oxidation reactions when compared to commercial 40 wt.% and 20% /Vulcan XC-72R (ETEK) catalysts. The mass activity increases 2.0x and 2.4x for methanol and ethanol oxidation reactions when compare with 40 and 20 Pt wt. % commercial catalysts, respectively. The Pt/CeO2−x/Vulcan XC-72R catalysts contained Pt nanoparticles growth within the cerium oxide through an occlusion electrodeposition method. These effects were systematically investigated using X-ray Diffraction (XRD), High Resolution Transmission Electron Microscopy (HR-TEM), and X-ray Photoelectron Spectroscopy (XPS).

During the last years, the authors have synthesized, characterized, and studied the adsorption properties of nitroprussides, Prussian blue analogues, akaganeites, MeAPOs, metal–organic frameworks, and extremely high specific surface amorphous silica, which allowed the storage of about 11 wt.% of hydrogen in the form of ammonia. In this sense, using the solid-state reaction method, sol–gel methodologies, together with aluminosilicate, high silica and non-aluminosilicate zeolite synthesis methods, were described, moreover was explained how to prepare active carbons along with the synthesis of Prussian blue analogues (PBAs) and nitroprussides (NPs). In addition, the characterization of the materials of interest applying X-ray diffraction, thermogravimetric analysis, DRIFTS, and room-temperature Mossbauer spectrometry was discussed. Besides, the concepts that define physical adsorption and examples of adsorption data, which were tested with the help of the Dubinin, osmotic adsorption and Langmuir-type isotherms, were defined. Later, the methodology was described for the measurement of adsorption data with the help of the volumetric method. Moreover, a description of the thermodynamics of adsorption, along with the methodology for the calculation of calorimetric data with the help of heat flow calorimeters together with the measurement of differential heats of adsorption data was developed. Finally, the different interaction forces that make possible adsorption were discussed.

In the course of the last years hexacyanoferrates have been widely studied; even though, the adsorption properties of Zn (II) hexacyanoferrate(II) (labelled here Zn-HII) have not been thoroughly considered. In addition, soft porous crystals, i.e., adsorbents that display structural flexibility have been, as well, extensively studied, however this property has not been reported for Zn (II) hexacyanoferrate(II). In this regard, the key questions addressed here were the synthesis and structural characterization of Zn-HII together with the investigation of their low (up to 1 bar) and high pressure (up to 30 bar) adsorption properties, to found if these materials show structural flexibility. Then, to attain the anticipated goals, structural characterizations were made with: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) and thermo-gravimetric analysis (TGA), simultaneously, with the investigation of the adsorption of carbon dioxide. As a result of the research process we concluded that the Zn-HII displayed Fm3m space group framework. Besides, the carbon dioxide adsorption investigation demonstrated the presence of the framework expansion effect together with an extremely high adsorption heat, properties that could be useful for the use of Zn(II) hexacyanoferrate(II) as an excellent adsorbent. (C) 2016 Elsevier B.V. All rights reserved.

Platinum was electrodeposited onto Y-zeolite and Y-zeolite (Y)/Vulcan XC-72R (V) to produce Pt/Y/V and Pt/Y catalysts using a rotating disk slurry electrode technique.

A mixture of akaganeite nanoparticles and sodium salts was synthesized and modified, first by washing, and then by Li exchange. The structural characterization of the produced materials was performed with: powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, thermogravimetric analysis, diffuse reflectance infrared Fourier transform spectrometry, Mossbauer spectroscopy and magnetization measurements. Additionally low pressure nitrogen and high pressure carbon dioxide adsorption experiments were performed. The sum of the characterization information made possible to conclude that the produced akaganeite phases crystallized in a structure exhibiting the symmetry of the I2/m space group, where the measured equivalent spherical diameter of the akaganeite crystallites yielded 9 nm, as well, the tested phases exhibited a standard behaviour under heating and displayed a superparamagnetic behaviour. Finally the high pressure carbon dioxide adsorption experiments demonstrated a pressure-responsive framework opening event due to a structural transformation of the adsorbent framework induced by the guest molecules. This fact opens new applications for akaganeite as a high pressure adsorbent. (C) 2015 Elsevier B.V. All rights reserved.

The key questions addressed here were: the structure elucidation and the investigation of the adsorption space and framework expansion effect of a Cu(II) hexacyanoferrate (III) polymorph (labeled Cu-PBA-I). The structural analysis was performed with a broad set of characterization methods. Additionally, a low and high pressure carbon dioxide adsorption investigation was performed, assuming, to comprehend the adsorption experiments, that the adsorbent plus the adsorbed phase were a solid solution. We concluded: that the Cu-PBA-I presented the following composition, K1/4Cu(II)[Fe(III)(CN)6]3/4⋄1/4nH2O, exhibited an antiferromagnetic behavior and displayed a thermally stable I4¯m2 space group lattice in the degassed state. Moreover, the low pressure adsorption study allowed the calculation of the micropore volume, W=0.09cm3/g and the isosteric heat of adsorption, qiso=19kJ/mol; further, the high pressure adsorption data revealed an extremely high adsorption capacity owing to a framework expansion effect. Finally, the DRIFTS spectrum of adsorbed CO2 displayed peaks corresponding to carbon dioxide physically adsorbed and interacting with electron accepting Lewis acid sites. Hence, was produced an excellent adsorbent which combine porosity and anti-ferromagnetism, antagonist properties rarely found together.