Synergistic Factors Affecting Catalytic Performance of Fe(II) Phthalocyanine @ Titania-Pillared Bentonite Nanocomposites in Styrene Production

The hybrid nanocatalytic system under study consisted of iron (II) phthalocyanine complex (FePc) of 0.5 – ~10 wt % loading immobilized in the bentonite interlayers modified by pillaring with titania nanoparticles (88 nm). Various interactions facing FePc complex were discussed through the changes in different characteristics assessed by adopting XRD, FTIR, ICP-EDX, TGA-DrTGA, TEM, N2 adsorption-desorption and H2-chemisorption techniques. Intercalated FePc molecules could evolve excessive silanol and aluminol sites through interaction with various clay-interlayer sites and titania pillar. By applying this FePc @ Ti-PILB nanocomposite in oxidative dehydrogenation of ethyl benzene, synergistic combination of factors influencing selective production of styrene confirmed the optimum turnover frequency with maximum selectivity to styrene at 3.4 wt % FePc loading. Below this loading, redox pair factor linked with dispersion and orientation mode of FePc was predominating. In higher loaded samples of considerable silanol sites, clay acid-base pair balance became prevailing

Potencijalna profilaktička uloga aminogvanidina u diabetičkoj retinopatiji i nefropatiji u eksperimentalnih životinja

This study sought to determine the potential prophylactic and antioxidant effects of aminoguanidine in experimentally induced diabetes. Four groups of Wistar rats, each composed of ten rats, were used. Two groups served as control. In group 3, diabetes was induced by a single intraperitoneal injection of streptozotocin (65 mg kg1). In group 4, diabetes was induced and treated with aminoguanidine 100 mg kg1 daily orally for 3 months. Levels of serum glucose, glutathione peroxidase, glutathione reductase and erythrocytes catalase were analyzed on day 90 of the experiment. Retinal and kidney specimens were examined histopathologically after sacrifice of the animals. A significant antioxidant effect of aminoguanidine and its prophylactic role in diabetic retinopathy and nephropathy were observed in experimental animals.U ovom radu ispitivano je potencijalno profilaktičko i antioksidativno djelovanje aminogvanidina u eksperimentalno induciranom dijabetesu. Ispitivanja su provedena na četiri skupine od 10 štakora. Dvije skupine bile su kontrolne skupine, u trećoj skupini dijabetes je induciran jednokratnom intraperitonealnom injekcijom streptozotocina 65 mg kg1, a u četvrtoj dijabetes je induciran i tretiran aminogvanidinom 100 mg kg1 dnevno, peroralno, tijekom 3 mjeseca. Devedeseti dan eksperimenta analizirane su koncentracije glukoze u serumu, glutation peroksidaze, glutation reduktaze i eritrocitne katalaze. Životinje su žrtvovane, a uzorci retine i bubrega ispitivani su histopatologiški. Uočen je značajni antioksidativni učinak aminogvanidina i njegova profilaktička uloga u dijabetičkoj retinopatiji i nefropatiji

Optimization of Redox Functionality Profiles of MoO3–V2O5/ TiO2 Composite Catalysts in Relation to Various Dispersion Patterns

Abstract: In the present study, a renewed approach was made to optimize the redox functionality of the well-known catalytic system MoO3-V2O5/ TiO2 (anatase) in relation to various dispersion patterns. Several types of composite catalysts were considered: xV/T (x of V2O5= 2-12 wt %), 6Mo-xV/T co-impregnates, yMo-8V/T co-impregnates (y of MoO3 = 3-9 wt %), 6Mo-doped 8V/T (coat 1) and 8V-doped Mo/T (coat 2). The samples were characterized by adopting the XRD, FTIR, ESR, TEM, N2 physisorption, high temperature H2-chemisorption and high temperature O2-chemisorptrion (HTOC), techniques. The redox reactivity was estimated in decomposition of H2O2 in highly concentrated solution, permitting the formation of several peroxo V intermediates. In xV/T system, the constancy of TON with loading indicated the involvement of single vanadia site, not sensitive to the surface dispersion, but rather depended on the nature of coordination of H2O2 molecules to VOx species. For different co-impregnates of Mo and V, the added molybdena, increasing the Lewis acidity, seemed to undergo a competitive interaction with titania to form non-reducible surface compound, with increased density of surface VOx patches. This was confirmed from H2-uptakes linked with highly stabilized V4+ species. The sample of coat 1had the same dispersion and reactivity patterns of the other members of co-impregnated series, with formation of non-reducible surface compound through Mo-O-V bridges. In coat 2 sample, the VOx species existed on the top surface of supported MoO3/TiO2 in a better dispersion state, with higher apparent density of surface patches, exhibiting comparable [A] and TON values to those of xV/T samples

Artichoke as a non-conventional precursor for activated carbon: Role of the activation process

Artichoke peels were used to produce activated carbon using chemical activation methods. Two activation protocols were compared: a two-step method A and a one-step method B. As newly used activating agents, KCl, CrCl3 and TiCl4 were compared. The results show that method B is superior to A. KOH with method B had an area of 2321 m2/g and a total pore volume 1.0071 cm3/g, of which 0.9794 cm3/g was confined to micropores. The corresponding values for KCl are 1731, 0.6925 and 0.6718. TiCl4 had lower but comparable values with those of KCl. CrCl3 appeared to be the least successful among the three newly used activating agents. The post-activation washing step strongly affects the characteristics of the final product. The differences among the effects of Zn, Cr and Ti are discussed in terms of the differences in polarizing power