14 research outputs found

    Influence of the strong metal support interaction effect (SMSI) of Pt/TiO2 and Pd/TiO2 systems in the photocatalytic biohydrogen production from glucose solution

    Get PDF
    Two different catalysts consisting of Pt/TiO2 and Pd/TiO 2 were submitted to diverse oxidative and reductive calcination treatments and tested for photocatalytic reforming of glucose water solution (as a model of biomass component) in H2 production. Oxidation and reduction at 850°C resulted in better photocatalysts for hydrogen production than Degussa P-25 and the ones prepared at 500°C, despite the fact that the former consisted in very low surface area (6-8 m2/g) rutile titania specimens. The platinum-containing systems prepared at 850°C give the most effective catalysts. XPS characterization of the systems showed that thermal treatment at 850°C resulted in electron transfer from titania to metal particles through the so-called strong metal-support interaction (SMSI) effect. Furthermore, the greater the SMSI effect, the better the catalytic performance. Improvement in photocatalytic behavior is explained in terms of avoidance of electron-hole recombination through the electron transfer from titania to metal particles

    Influence of the strong metal support interaction effect (SMSI) of Pt/TiO2 and Pd/TiO2 systems in the photocatalytic biohydrogen production from glucose solution

    No full text
    Two different catalysts consisting of Pt/TiO2 and Pd/TiO 2 were submitted to diverse oxidative and reductive calcination treatments and tested for photocatalytic reforming of glucose water solution (as a model of biomass component) in H2 production. Oxidation and reduction at 850°C resulted in better photocatalysts for hydrogen production than Degussa P-25 and the ones prepared at 500°C, despite the fact that the former consisted in very low surface area (6-8 m2/g) rutile titania specimens. The platinum-containing systems prepared at 850°C give the most effective catalysts. XPS characterization of the systems showed that thermal treatment at 850°C resulted in electron transfer from titania to metal particles through the so-called strong metal-support interaction (SMSI) effect. Furthermore, the greater the SMSI effect, the better the catalytic performance. Improvement in photocatalytic behavior is explained in terms of avoidance of electron-hole recombination through the electron transfer from titania to metal particles. © 2011 Elsevier B.V. All rights reserved.Dr Colmenares wants to express his sincere gratitude to the European Commission for the financial support. This research was supported by a Marie Curie International Reintegration Grant within the 7th European Community Framework Programme. Financial support from Junta de Andalucia ( and ) and MICINN (, and ) is also gratefully acknowledgedPeer Reviewe

    Total polyphenol intake and breast cancer risk in the Seguimiento Universidad de Navarra (SUN) cohort

    No full text
    Polyphenols are a wide family of phytochemicals present in diverse foods. They might play a role in cancer development and progression. In vivo and in vitro studies have suggested beneficial properties and potential mechanisms. We aimed to evaluate the association between total and main classes of polyphenol intake and breast cancer (BC) risk in the Seguimiento Universidad de Navarra project – a prospective Mediterranean cohort study. We included 10 713 middle-aged, Spanish female university graduates. Polyphenol intake was derived from a semi-quantitative FFQ and matching food consumption data from the Phenol-Explorer database. Women with self-reported BC were asked to return a copy of their medical report for confirmation purposes; death certificates were used for fatal cases. Cox models were fitted to estimate multivariable-adjusted hazard ratios (HR) and 95 % CI for the association between tertiles (T) of polyphenol intake and BC. After 10·3 years of median follow-up, 168 probable incident BC cases were identified, out of which 100 were confirmed. We found no association between polyphenol intake and the overall BC risk. Nevertheless, we observed a significant inverse association between total polyphenol intake and BC risk for postmenopausal women, either for probable or only for confirmed cases (HRT3 v. T1 0·31 (95 % CI 0·13, 0·77; Ptrend=0·010)). Also, phenolic acid intake was inversely associated with postmenopausal BC. In summary, we observed no significant association between total polyphenol intake and BC risk. Despite a low number of incident BC cases in our cohort, higher total polyphenol intake was associated with a lower risk of postmenopausal BC

    Total polyphenol intake and breast cancer risk in the Seguimiento Universidad de Navarra (SUN) cohort

    No full text
    Polyphenols are a wide family of phytochemicals present in diverse foods. They might play a role in cancer development and progression. In vivo and in vitro studies have suggested beneficial properties and potential mechanisms. We aimed to evaluate the association between total and main classes of polyphenol intake and breast cancer (BC) risk in the Seguimiento Universidad de Navarra project – a prospective Mediterranean cohort study. We included 10 713 middle-aged, Spanish female university graduates. Polyphenol intake was derived from a semi-quantitative FFQ and matching food consumption data from the Phenol-Explorer database. Women with self-reported BC were asked to return a copy of their medical report for confirmation purposes; death certificates were used for fatal cases. Cox models were fitted to estimate multivariable-adjusted hazard ratios (HR) and 95 % CI for the association between tertiles (T) of polyphenol intake and BC. After 10·3 years of median follow-up, 168 probable incident BC cases were identified, out of which 100 were confirmed. We found no association between polyphenol intake and the overall BC risk. Nevertheless, we observed a significant inverse association between total polyphenol intake and BC risk for postmenopausal women, either for probable or only for confirmed cases (HRT3 v. T1 0·31 (95 % CI 0·13, 0·77; Ptrend=0·010)). Also, phenolic acid intake was inversely associated with postmenopausal BC. In summary, we observed no significant association between total polyphenol intake and BC risk. Despite a low number of incident BC cases in our cohort, higher total polyphenol intake was associated with a lower risk of postmenopausal BC
    corecore