Irradiation of H-ETS-10 in the presence of adsorbed methanol or ethene causes photoreduction of Ti(IV) to Ti(III); photoreduction does not occur for Na, K-ETS-10, but a photoinduced polymerization of ethene is observed.

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Glycerol upgrading to diglycerols in the presence of basic (Na+ or Cs+) ion-exchanged (FAU or BEA) zeolite catalysts was studied in a liquid-phase batch rector at 260 degrees C under normal pressure. Homogeneous NaHCO3 and CsHCO3 catalysts were studied for comparison. All the catalysts, including NaHCO3 and CsHCO3, displayed the same conversion-selectivity relationship. The selectivity to linear diglycerols decreased at higher conversions/reaction times owing to the consecutive formation of higher oligomers, with preferential further conversion of alpha,alpha'-diglycerol. The maximum yield of linear diglycerols was limited to about 30 %. The activities of the zeolites followed the order X>Y>Beta, independent of the alkali ion present. Catalysis by the zeolites starts with an induction period attributed to a slow leaching of alkaline cations from the zeolite. Thereafter, the reaction is characterized by a progressive loss of the microporous structure of the zeolite and increasing overlap of heterogeneous and homogeneous catalysis, where, primarily, the activity depends on the cation content of the zeolite.

A detailed characterization study is reported of ETS-10 subjected to ammonium ion exchange and subsequent sodium ion back exchange. It is shown that although such ion exchange leaves the crystallinity of ETS-10 measured by X-ray powder diffraction unchanged, other techniques reveal that the structure becomes locally damaged. In particular, there is partial dissolution of silica from the outer regions of ETS-10 crystallites under low pH conditions, exposing titania-rich surface sites and substantially modifying the photoreactivity of the material.

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