R.M. Lago

Bio: R.M. Lago is an academic researcher from University of Oxford. The author has contributed to research in topics: Catalysis & Halide. The author has an hindex of 3, co-authored 4 publications receiving 588 citations.

Redox properties of molten salts for methane activation

Abstract: Molten salt mixtures have been tested in a redox mode as catalysts for the activation of methane at 750 °C. It is found that after pre-treatment with dioxygen a transition metal halide/ sodium vanadate melt can convert methane selectively to C2+ products in the absence of molecular oxygen. The melt can be reactivated by passing dioxygen. Electron paramagnetic resonance studies of the quenched samples showed that the transition metal ions are reduced by methane and can be reoxidised by dioxygen. It is also found that higher C2+ selectivity, C2+ yield and C2H4/C2H6 ratio are promoted by added transition metal chlorides and, surprisingly, also by the corresponding metal bromides. It supports the suggestion that surface modification by halogen is more important than gas radical reactions. Comparison of the molten mixtures under redox and cofeed conditions showed that the former gave a higher C2+ selectivity, but no oxygenated products whereas formaldehyde was only detected in the cofeed conditions.

Investigation of Molten Cobalt Halide/Sodium Metavanadate Mixtures as Redox Catalysts for the Oxidative Coupling of Methane

Abstract: Molten mixtures of sodium metavanadate and cobalt halide have been tested as catalysts for the activation of methane at 750°C in redox mode. It is found that these melts can convert methane selectively to C2+ products in the absence of molecular oxygen. The initial activity and selectivity of the melt can then be restored after dioxygen treatment. It is also found that the addition of cobalt chloride gives a higher CH4 conversion, C2+ selectivity and C2H4/C2H6 ratio than pure sodium metavanadate. Surprisingly, addition of cobalt bromide shows a similar enhancement. IR and ESR spectra of quenched catalyst samples showed that the cobalt and vanadium ions are reduced by methane and can be reoxidised by dioxygen

Dispersion and functionalization of carbon nanotubes for polymer-based nanocomposites: a review

Abstract: Carbon nanotubes (CNTs) hold the promise of delivering exceptional mechanical properties and multi-functional characteristics. Ever-increasing interest in applying CNTs in many different fields has led to continued efforts to develop dispersion and functionalization techniques. To employ CNTs as effective reinforcement in polymer nanocomposites, proper dispersion and appropriate interfacial adhesion between the CNTs and polymer matrix have to be guaranteed. This paper reviews the current understanding of CNTs and CNT/polymer nanocomposites with two particular topics: (i) the principles and techniques for CNT dispersion and functionalization and (ii) the effects of CNT dispersion and functionalization on the properties of CNT/polymer nanocomposites. The fabrication techniques and potential applications of CNT/polymer nanocomposites are also highlighted.

Load transfer and deformation mechanisms in carbon nanotube-polystyrene composites

Abstract: Multiwall carbon nanotubes have been dispersed homogeneously throughout polystyrene matrices by a simple solution-evaporation method without destroying the integrity of the nanotubes. Tensile tests on composite films show that 1 wt % nanotube additions result in 36%–42% and ∼25% increases in elastic modulus and break stress, respectively, indicating significant load transfer across the nanotube-matrix interface. In situ transmission electron microscopy studies provided information regarding composite deformation mechanisms and interfacial bonding between the multiwall nanotubes and polymer matrix.