Makgwane, Peter RRay, Suprakas S2013-12-122013-12-122013-07Makgwane, P.R and Ray, S.S. 2013. Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen. Journal of Molecular Catalysis A: Chemical, vol. 373, pp 1-111381-1169http://ac.els-cdn.com/S1381116913000794/1-s2.0-S1381116913000794-main.pdf?_tid=d25e429a-6269-11e3-8cd6-00000aacb360&acdnat=1386769419_8abccb1ca89385a36493c9057ebfaa8dhttp://hdl.handle.net/10204/7117https://www.sciencedirect.com/science/article/pii/S1381116913000794https://doi.org/10.1016/j.molcata.2013.02.017Copyright: 2013 Elsevier. This is an ABSTRACT ONLY. The definitive version is published in Journal of Molecular Catalysis A: Chemical, vol. 373, pp 1-11Highly dispersed, nanosized ruthenium (Ru) particles anchored on carbon nanofibers (CNFs) with varying Ru loadings (1–7 wt.%) showed effective catalytic activity in the aerobic oxidation of p-cymene using molecular oxygen. The activity of the Ru catalysts was influenced by the structural properties that resulted from the different metal loadings and by various reaction variables, such as the temperature, the amount of catalyst and the type of radical–initiator substrate. Under optimized reaction conditions, the 3%Ru/CNF catalyst exhibited excellent performance with a selectivity of 42% toward primary cymene hydroperoxide (PCHP) and 33% toward tertiary cymene hydroperoxide (TCHP) at 55% p-cymene conversion achieved within 5 h at 90 C. The results demonstrated that the direct participation of the catalyst in p-cymene C-H bond activation occurred via catalytic decomposition of tertiary-butyl hydroperoxide (TBHP), which was added as an initiator, into a free-radical chain initiator rather than the direct H-atom abstraction by the catalyst itself. The catalytic efficacy displayed by the Ru/CNF catalysts provides encouraging results for the activation of C H bonds of liquid-phase alkyl aromatic hydrocarbons, such as p-cymene, toward the introduction of an oxygen atom. The catalyst was reusable for five consecutive reaction cycles without appreciable loss of activity. Moreover, Ru/CNF catalyst was active for extended substrate scope application in the oxidation of other alkyl-substituted aromatics.enRutheniumNanocatalystLiquid phase oxidationp-CymeneTertiary cymene hydroperoxidePrimary cymene hydroperoxideArticleMakgwane, P. R., & Ray, S. S. (2013). Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen. http://hdl.handle.net/10204/7117Makgwane, Peter R, and Suprakas S Ray "Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen." (2013) http://hdl.handle.net/10204/7117Makgwane PR, Ray SS. Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen. 2013; http://hdl.handle.net/10204/7117.TY - Article AU - Makgwane, Peter R AU - Ray, Suprakas S AB - Highly dispersed, nanosized ruthenium (Ru) particles anchored on carbon nanofibers (CNFs) with varying Ru loadings (1–7 wt.%) showed effective catalytic activity in the aerobic oxidation of p-cymene using molecular oxygen. The activity of the Ru catalysts was influenced by the structural properties that resulted from the different metal loadings and by various reaction variables, such as the temperature, the amount of catalyst and the type of radical–initiator substrate. Under optimized reaction conditions, the 3%Ru/CNF catalyst exhibited excellent performance with a selectivity of 42% toward primary cymene hydroperoxide (PCHP) and 33% toward tertiary cymene hydroperoxide (TCHP) at 55% p-cymene conversion achieved within 5 h at 90 C. The results demonstrated that the direct participation of the catalyst in p-cymene C-H bond activation occurred via catalytic decomposition of tertiary-butyl hydroperoxide (TBHP), which was added as an initiator, into a free-radical chain initiator rather than the direct H-atom abstraction by the catalyst itself. The catalytic efficacy displayed by the Ru/CNF catalysts provides encouraging results for the activation of C H bonds of liquid-phase alkyl aromatic hydrocarbons, such as p-cymene, toward the introduction of an oxygen atom. The catalyst was reusable for five consecutive reaction cycles without appreciable loss of activity. Moreover, Ru/CNF catalyst was active for extended substrate scope application in the oxidation of other alkyl-substituted aromatics. DA - 2013-07 DB - ResearchSpace DP - CSIR KW - Ruthenium KW - Nanocatalyst KW - Liquid phase oxidation KW - p-Cymene KW - Tertiary cymene hydroperoxide KW - Primary cymene hydroperoxide LK - https://researchspace.csir.co.za PY - 2013 SM - 1381-1169 T1 - Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen TI - Nanosized ruthenium particles decorated carbon nanofibers as active catalysts for the oxidation of p-cymene by molecular oxygen UR - http://hdl.handle.net/10204/7117 ER -