Now showing 1 - 4 of 4
- PublicationDifferent dispersions of group II catalysts over SBA 15 and MCM-41: Effects on transesterification reactivityActivities of CaO catalysts on SBA-15 and MCM-41 have been compared in transesterification and SBA-15 supported samples invariably more active than those on MCM-41. Increased activity is not due to diffusional effects (as measured using substrates of differing size) but rather to increased dispersion of CaO on SBA-15 (as measured using NOx TPD). The effect, i.e. increased reactivity of SBA-15 supported catalysts being related to increased dispersion, is also noted in supported BaO catalysts while supported MgCO3 catalysts show little variation in dispersion (or in reactivity) as a function of the support used.
Scopus© Citations 9 313
- PublicationThe nature of surface deposits following valeric acid interactions with Al2O3-supported Alkaline Earth Oxide catalysts: Towards cellulosic biofuelsTwo Al2O3-supported alkaline earth metal oxide catalysts (MgO and BaO) were contacted with valeric acid at 250 °C. Each formed amounts of 5-nonanone (BaO more than MgO). A significant deposition of hydrocarbonaceous material onto the catalyst surface is noted. This adsorbed material is characterised using TGA and FTIR and relates to a carboxylate species.
453Scopus© Citations 2
- PublicationThe reactivity of mesoporous silica modified with acidic sites in the production of biodieselThis work has studied a range of acidic catalysts which have been prepared through the modification of mesoporous silica materials. Specifically we have prepared –SO3H modified materials (in the presence and absence of a hydrophobic component) and–COOH and –CN materials. We have characterized these catalysts using TEM, TGA, TPD of probe molecules and IR and we have analysed their activity in the esterification of octanoic acid and the transesterification of triacetin. Activity in the esterification reaction (in which all catalysts are active) is not determined by the acid site concentration of the catalyst while the activity of active catalysts in the transesterification reaction (in which only –SO3H materials are active) appears related to acid site concentration.
657Scopus© Citations 23
- PublicationThe Preparation of Group II Oxide Catalysts Through Acetate Calcination: The Influence of a Support on the Nature of the Final Catalyst.The preparation of supported and unsupported group II oxide catalysts through oxidation of analogous group II acetates (Mg, Ca and Ba) in the presence and absence of a mesoporous silica material (SBA-15) was analysed using TGA. In the absence of the mesoporous support the acetates oxidised at different temperatures with a stability trend whereby Mg
367Scopus© Citations 2