Catalytic hydrotreatment or hydrodeoxygenation (HDO) has been researched extensively with the crude bio-oil and its model compounds over conventional sulfided Ni(Mo), Co(Mo) catalysts and supported noble metal catalysts. These types of catalysts showed themselves unsuitable for the target HDO process, which resulted in an urgent need to search for a new catalytic system meeting such requirements as low cost, stability against coke formation and leaching of active components due to adverse effect of the acidic medium (bio-oil). In the present work a series of Ni-based catalysts with different stabilizing components has been tested in the hydrodeoxygenation (HDO) of guaiacol (2-methoxyphenol), bio-oil model compound. The process has been carried out in an autoclave at 320 °C and 17 MPa H2. The main products were cyclohexane, 1-methylcyclohexane-1,2-diol, and cyclohexanone. The reaction scheme of guaiacol conversion explaining the formation of main products has been suggested. The catalyst activity was found to rise with an increase in the active component loading and depend on the catalyst preparation method. The most active catalysts in HDO of guaiacol were Ni-based catalysts prepared by a sol–gel method and stabilized with SiO2 and ZrO2. According to TPR, XRD, XPS, and HRTEM, the high activity of these catalysts correlates with the high nickel loading and the high specific area of active component provided by the formation of nickel oxide–silicate species. The effect of temperature on the product distribution and catalyst activity in the target process (HDO) has been investigated as well. The catalysts were shown to be very promising systems for the production of hydrocarbon fuels by the catalytic upgrading of bio-oil.

Ni-based sol–gel catalysts as promising systems for crude bio-oil upgrading: Guaiacol hydrodeoxygenation study

XPS study of copper aluminate catalysts

The use of 9% La2NiO4/γ-Al2O3 (9NLA) as a catalyst for CO2 reforming of methane to syngas has been investigated in a fixed-bed reactor. The results revealed that the yields of CO and H2 over a 800 °C calcined 9NLA catalyst were remarkably higher than those over a 500 °C calcined one. The BET data confirmed that the properties, such as specific surface area, pore volume and average pore diameter, of a used and a regenerated catalyst were similar to those of a fresh catalyst. Temperature-programmed reduction (TPR) and X-ray photoelectron spectroscopy (XPS) results indicated that the activity of the catalyst depended largely on the degree of catalyst reduction, as well as on the dispersion of metallic nickel. The results of X-ray diffraction (XRD) and temperature-programmed oxidation (TPO)-MS studies demonstrated that the formation of carbon species on the catalyst could be related to the structure and surface composition of the catalyst. With the rise in temperature for catalyst calcination, there was a decline in coke formation due to the formation of a stable NiAl2O4 spinel structure.

Carbon deposition and catalyst stability over La2NiO4/γ-Al2O3 during CO2 reforming of methane to syngas

Hollow, spherical nitrogen-rich porous carbon shells were prepared as supercapacitor electrode materials through the carbonization of structure-controlled porous organic frameworks at high temperature. The structure and electrochemical properties of the resulting carbonized materials were systematically characterized. Experimental results revealed that the nitrogen-rich hollow carbon spheres obtained at 800 °C were a kind of amorphous carbon with micropores on the shell frame and with specific surface areas as high as 525 m2 g–1. The prepared porous carbon possessed a specific capacitance of 230 F g–1 at a current density of 0.5 A g–1 and could retain ∼98% of the initial capacitance after 1500 successive charge–discharge cycles. Electrochemical impedance spectroscopy indicated that the material has a small equivalent series resistance (0.62 Ω). All of these values demonstrated that the prepared porous carbon is a promising supercapacitor material. The proposed method represents a simple approach towards t...

Hollow, Spherical Nitrogen-Rich Porous Carbon Shells Obtained from a Porous Organic Framework for the Supercapacitor

Investigation of epitaxial LaNiO3−x thin films by high-energy XPS

Esca investigations of some NiO/SiO2 and NiO—Al2 O3 /SiO2 catalysts

Die N-Acyl-thio- und -selenoharnstoffe bilden als 1,3-Dichalkogenketone relativ einfach zugangliche stabile Schwermetallchelate. Aus der Messung der chemischen Verschiebung der N 1s-, S 2p-, bzw. Se 3p- und Schwermetall nl-ESCA-Linien kann man den Schlus ziehen, das die σ-Bindung des Zentralatoms uber den Sauerstoff erfolgt. Die S- und Se-Atome gehen eine dative Bindung ein, wobei sich ihre Elektronendichte erniedrigt. Das Auftreten zweier N-Signale last sich durch die bei der Komplexbildung erforderliche Deprotonierung verstehen.



ESCA Investigations on Heavy Metal Chelates of Substituted N-acyl-thio- and -selenoureas



N-acylthio- and -selenoureas give as 1,3-dichalcogenketones stable chelates of heavy metals, which are easy to synthesize. From the measurement of the chemical shifts of the N1s-, S2p- or Se3p- and metal nl-ESCA lines follows, that the bonding between the ligand and the central atom involves a σ-bond of oxygen and a donor bond of sulfur and selenium, with a decrease of the electronic density on S or Se, resp. The appearence of two N1s-signals can be explained by deprotonation, which is necessary for the formation of the complex.

ESCA‐Untersuchungen an Schwermetallchelaten substituierter N‐Acyl‐thio‐ und ‐selenoharnstoffe

Komplexverbindungen des Typs 






, mit M = Fe, Co und 






Thiodibenzoylmethanat (TDBM) und N-(Morpholinothiocarbamoyl)-benzamidat (MTBA), wurden synthetisiert. Mittels Molmassebestimmung, IR- und ESCA-Spektroskopie sowie magnetochemischen Untersuchungen wurde nachgewiesen, das der Eisenkomplex 1 als schwefelverbruckter Zweikern-komplex [Fe(TDBM)2NO]2 vorliegt, in dem jedes Eisenatom sechsfach koordiniert ist. Die Kobalt-komplexe Co(TDBM)2NO, 2, und Co(MTBA)2NO, 3, liegen monomer in quadratisch-pyramidaler Struktur vor. In allen Fallen weisen die ESCA-Spektren formal dreiwertige Zentralmetalle mit negativ geladenem Nitrosylliganden aus.



Nitrosyl Metal Coordination Compounds. I. Synthesis and Properties of Iron and Cobalt Complexes of the Type








Complex compounds of the type 






, with M = Fe, Co and 






thiodibenzoylmethanate (TDBM) and N-(morpholinothiocarbamoyl)-benzamidate (MTBA) have been synthesized. It has been established by means of molecular weigths measurements, IR and ESCA spectroscopy, and magnetic investigations that the iron complex 1 is a sulfur bridged dimeric molecule [Fe(TDBM)2NO]2, where each iron atom has the coordination number six. The cobalt complexes Co(TDBM)2NO, 2, and Co(MTBA)2NO, 3, are both monomeric with square pyramidal structures. The ESCA spectra are in each case in accordance with the formal oxidation number three of the central metal and a negative charged nitrosyl ligand.

E. K. Žumadilov

Papers

Esca investigations of some NiO/SiO2 and NiO—Al2 O3 /SiO2 catalysts

ESCA‐Untersuchungen an Schwermetallchelaten substituierter N‐Acyl‐thio‐ und ‐selenoharnstoffe

Nitrosyl‐Metallkoordinationsverbindungen. I. Synthese und Eigenschaften von Eisen‐ und Kobaltkomplexen des Typs