Többfunkciós nemesfém/zeolit-katalizátorok szerepe motorhajtó anyagok minőség-javításában = The role of multifunctional noble metal/zeolite catalysts in upgrading of motor fuels

Hidrogénező finomítással sikerült a korszerű kívánalmaknak megfelelő motorhajtó anyagokhoz jutni úgy, hogy egyidejűen ment végbe a kén, a nitrogén és a nem kívánatos aromások eltávolítása minimális oktánszám- ill. a cetánszám-veszteséggel, esetlegesen növeléssel és maximális folyadékhozammal. Motorbenzineket 10 ppm alá kéntelenítettünk zeolit-hordozós platina-katalizátoron még akkor is, amikor jelentékeny hányaduk a magas kéntartalmú krakkbenzinből származott, melyben a kén zöme a nehezen kezelhető benzotioféntől ered. A kéntelenítéssel egyidejű paraffin-izomerizáció különösen a könnyű párlatoknál (pl. a hexán-frakciónál) jelentős, amikor az alapanyagban levő benzol hidrogéneződött. Rendszerünkben az olefinek telítése (ami oktánszám csökkenésre vezet) jóval kisebb mértékű, mint konvencionális kéntelenítő katalizátorokon. A gázolajok 10 ppm-ig történő kéntelenítésekor bizonyos esetekben a reakció nagy mértékben lelassul. Megállapítottuk, hogy ezért a 2,6-dialkil-dibenzotiofének a felelősek, melyek kéntelenítése sztérikusan gátolt és ezért csak a gyűrű telítése után megy végbe. Ilyenkor nagy hidrogénező aktivitású Ni,Mo/Al2O3-katalizátor alkalmazásával a reakciókörülményeket a maghidrogénezésnek megfelelően kell beállítani. A kéntelenítéssel egyidejűen végbemenő hidrodezaromatizálás alkalmas katalizátora a Pt,Pd/USY, melyen a denitrifikáció is lejátszódik. Ezt követően ugyanezen a katalizátoron a naftének hidrogénezésével pedig megnövelhető a gázolaj cetánszáma. | Gasoline and diesel oil of high quality were produced by new hydrotreatment methods. Sulphur, nitrogen, and undesired aromatics were simultaneously removed with minimum loss of octane and cetane number, respectively. FCC gasolines containing the most hardly removable benzothiophene were desulfurized to 10 ppm on zeolite supported platinum. Hydrodesulfurization was accompanied by paraffin isomerization compensating to some extent the octane loss by hydrogenation of benzene present in hexane fraction. Olefin saturation resulting also in octane loss was essentially lower on the evaluated noble metal catalyst than over commercial desulfurizing contacts. Desulfurization of gas oil to 10 ppm slows down since 2,6-dialkyl-dibenzothiophenes of lowest reactivity accumulate. Their desulfurization is sterically hindered and can take place after saturation of aromatic rings. Catalysts like Ni,Mo/Al2O3 of high hydrogenation activity are required under conditions favorable for ring saturation. A suitable catalyst for simultaneous hydrodesulfurization, hydrodenitrogenation and hydrodearamatization is the evaluated Pt,Pd/USY. Hydrogenation of naphtenes in a successive step on the same catalyst increases the cetane number of gas oil

Indium an efficient co-catalyst in novel Cu or Ni catalysts for selective reduction of biomass derived fatty acids to alcohols, in Indium: Properties, Technological Applications and Health Issues

Supported copper or especially nickel catalysts are very important for hydrogenation of various organic compounds in the practice. Activity, selectivity and stability can be greatly improved using co-catalysts: e.g. chromium compounds with Cu (Adkins catalyst for fatty alcohol production) or molybdenum compounds with Ni (for hydrodesulfurization [HDS], hydrodeoxygenation [HDO], hydrodenitrogenation [HDN], etc. catalysts in petroleum refining. Recently, we discovered novel highly efficient bimetallic supported catalysts which were exceedingly active and selective in the hydrodeoxygenation (HDO) of octanoic acid to octanol at moderate pressure and temperature in addition very effective in reduction of acetic acid to ethanol. The catalysts contained indium as co-catalyst and a metal of high hydrogenation activity, such as, copper or nickel, on various support. A significant synergism can be observed when indium with another metal of hydrogenation activity is applied. Appearance of Cu2In or Ni2In phases, intermetallic compounds on the surface of metal particles results in significant increase of desired hydrogenation activity, i.e., in stepwise hydrogenation of carboxylic acids stopped at alcohol formation and in inhibiting hydrogenations when hydrodecarbonylation of carboxylic acids (loss of one carbon atom) and hydrogenolysis of hydrocarbon products (loss of further carbon atoms) proceed. Moreover, in presence of mobile indium atoms or of indium containing nano clusters mono- or bimolecular alcohol dehydration capability of the support is selectively poisoned. In order to have more information about the role of indium, experiments are carried out using quite different hydrogenation metals, Cu and Ni. Hydrogenation experiments are carried out with long chain fatty acid like octanoic acid for production of octyl alcohol and short chain acetic acid (produced in large amounts from biomass) for production of ethyl alcohol, ethyl acetate or acetaldehyde. The main question is how the co-catalyst second metal of moderate hydrogenation activity as gallium, cadmium, tin, but first of all indium, modify the activity of the supported hydrogenation metal and the surface properties of the support

Oxid-bázisú bevonatrendszerek, réteges szekezetű anyagok szintézise és felületi tulajdonságainak vizsgálata = Synthesis and surface characterization of oxide-based coatings and layer-structured materials“.

Prekurzor sók vizes, illetve alkoholos oldatából szol-gél eljárással titánlemez hordozón hőkezeléssel kialakított IrO2, RuO2, SnO2 egykomponensű rendszerek, valamint IrO2 – SnO2, RuO2 – SnO2, IrO2 – Ta2O5, illetve RuO2 – IrO2 – SnO2 vegyesoxid filmek képződési mechanizmusának in situ tanulmányozását végeztük el. A bevonat tulajdonságait jelentősen befolyásoló szekunder reakciókat (intramolekuláris hidrolízis, felületi karbonilok, karboxilátok, karbonátok, Zundel-típusú szerkezetek képződése és bomlása) részletesen elemeztük. Összefüggést mutattunk ki a filmkialakulás hőmérséklete és a bevonat összetétele, illetve az elektrokémiai aktivitás és a bevonat nemesfém-tartalma között. Gyógyszeripari technológiai szennyvíz, illetve fenolát-tartalmú víz detoxikálására a kifejlesztett katalitikus aktivitású bevonatok segítségével sikeres kísérleteket végeztünk. Kaolinit nano-komplexek, mechanokémiai úton módosított felületű, illetve OH-csoportokat tartalmazó ásványok szerkezetének, bomlásmechanizmusának szisztematikus vizsgálatát végeztük el. A karbamid nano-komplexbe történő beépülési mechanizmusára vonatkozóan új modellt állítottunk fel. A mechanikai tulajdonságok javítása céljából polimerbe ágyazható, nanométer-tartományba eső delaminált kaolinit előállítására sikeres előkísérleteket végeztünk. | A detailed study of the formation mechanism of IrO2, RuO2, SnO2 one-components systems as well as IrO2 – SnO2, RuO2 – SnO2, IrO2 – Ta2O5, and RuO2 – IrO2 – SnO2 mixed oxide coatings prepared from aqueous and alcoholic precursor solutions onto titanium metal supports by heat treatment has been carried out under in situ conditions. The role of the side reactions significantly influencing the coating characteristics (intramolecular hydrolysis, formation and subsequent decomposition of surface carbonyls, carboxylates, carbonates, Zundel-type structures) was identified and described in detail. Close correlations were found between the film evolution temperature and coating composition as well as between the electrochemical activity and the noble-metal content of the film. The coatings were successfully used for the detoxification of pharmaceutical process waste water and phenolate-containing water. The systematic study of the structure and decomposition mechanism of organo-clay nano-complexes, mechanochemically modified kaolinite surfaces and minerals containing OH-groups has been carried out. A new model has been proposed for the mechanism of urea incorporation in the nano-complex formed. Successful preliminary experiments were made for the delamination of kaolinite and for the incorporation of the nano-sized mineral thus formed into polymer matrices

Acetic acid hydroconversion over mono-and bimetallic indium doped catalysts supported on alumina and silicas of various textures

Abstract Consecutive hydroconversion of acetic acid (AA) to ethanol was compared over monometallic and novel bimetallic (containing In as guest metal) catalysts on alumina and silica supports (inter alia highly ordered SBA-15) of different porosity and pore structure. The transformation was studied in a fixed bed, flow-through reactor in the temperature range of 220–380°C using hydrogen flow at 21 bar total pressure. AA hydroconversion activity of Cu and Pt catalysts and the yield of selectively produced alcohol were increased drastically by applying SBA-15 as highly ordered, mesoporous silica support instead of alumina. The most active nickel catalysts do not allow the selective addition of hydrogen to carbon-oxygen bonds independently of supports producing mainly CH4; however, indium doping can completely eliminate the hydrodecarbonylation activity as found in earlier studies. The textural properties of studied silica supports of various textures such as SBA-15, CAB-O-SIL, and Grace Sylobead have a profound impact on the catalytic performance of Ni and Ni2In particles.</jats:p

Cu and Cu2In nanoparticles supported on amorphised zeolites for the selective reduction of biomass derived carboxylic acids to alcohols

Octanoic acid (OA) was used as reactant with medium chain length to model the aliphatic carboxylic acids which can be produced by catalytic, thermochemical or biological degradation of biomass. A flow through reactor was applied at 21 bar total pressure (in general at 20 bar hydrogen and 1 bar octanoic acid partial pressures) and 330-380 °C. Cu A-, X- and Y-zeolite based catalysts were pretreated in hydrogen flow at 450 °C. During reduction/dehydration A- and X-zeolite structures collapsed and aluminosilicate supported copper catalysts were formed, which contain copper nanoparticles in high dispersion. The catalyst samples were modified by In2O3 co-catalyst. Fatty acid conversion activity of amorphized zeolite supported Cu catalysts and the yield of selectively produced alcohol can be increased drastically by In2O3 addition. Appearance of metallic indium can effectively rein in the step by step catalytic reduction at alkanol formation previous to dehydration of alcohols to alkenes and ethers

Chronic Amyloid beta Oligomer Infusion Evokes Sustained Inflammation and Microglial Changes in the Rat Hippocampus via NLRP3

Microglia are instrumental for recognition and elimination of amyloid beta1-42 oligomers (AbetaOs), but the long-term consequences of AbetaO-induced inflammatory changes in the brain are unclear. Here, we explored microglial responses and transciptome-level inflammatory signatures in the rat hippocampus after chronic AbetaO challenge. Middle-aged Long Evans rats received intracerebroventricular infusion of AbetaO or vehicle for 4weeks, followed by treatment with artificial CSF or MCC950 for the subsequent 4weeks. AbetaO infusion evoked a sustained inflammatory response including activation of NF-kappaB, triggered microglia activation and increased the expression of pattern recognition and phagocytic receptors. Abeta1-42 plaques were not detectable likely due to microglial elimination of infused oligomers. In addition, we found upregulation of neuronal inhibitory ligands and their cognate microglial receptors, while downregulation of Esr1 and Scn1a, encoding estrogen receptor alpha and voltage-gated sodium-channel Na(v)1.1, respectively, was observed. These changes were associated with impaired hippocampus-dependent spatial memory and resembled early neurological changes seen in Alzheimer's disease. To investigate the role of inflammatory actions in memory deterioration, we performed MCC950 infusion, which specifically blocks the NLRP3 inflammasome. MCC950 attenuated AbetaO-evoked microglia reactivity, restored expression of neuronal inhibitory ligands, reversed downregulation of ERalpha, and abolished memory impairments. Furthermore, MCC950 abrogated AbetaO-invoked reduction of serum IL-10. These findings provide evidence that in response to AbetaO infusion microglia change their phenotype, but the resulting inflammatory changes are sustained for at least one month after the end of AbetaO challenge. Lasting NLRP3-driven inflammatory alterations and altered hippocampal gene expression contribute to spatial memory decline