A Highly active, time stable, and water resistant, Hombikat TiO2 supported Mn catalyst has been developed for the selective reduction of NO by NH3 [Eq. (1)]. The analogous Cu and Cr supported catalysts also provide 100 % N2 selectivity at ≤120°C. Lewis acidity, redox properties, and a high surface metal oxide concentration are essential for good catalytic performance.

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Benzyl alcohol is oxidized selectively to benzaldehyde with high yield, with a little formation of benzylbenzoate, by molecular oxygen over a reusable nano-size gold catalyst supported on U 3 O 8 , MgO, Al 2 O 3 or ZrO 2 in the absence of any solvent.Liquid phase oxidation of benzyl alcohol is an important preferred reaction practically for the production of chlorine-free benzaldehyde, without loss of carbon in the form of CO 2 (a geenhouse gas). The preparation of benzaldehyde by reacting benzyl alcohol with stoichiometric or excess amounts of potassium or ammonium permanganate in aqueous acidic medium 1 is not environmentally benign at all, because of the formation of a large amount of toxic waste. A few studies on the benzyl alcoholto-benzaldehyde oxidation by H 2 O 2 or O 2 in the presence of organic solvent, using different solid catalysts, such as Pd/C, 2 Pd(II) hydrotalcite, 3 Pd-Ag/pumice, 4 Ru-Co-Al hydrotalcite, 5 Ni-containing hydrotalcite 6,7 and nano-size NiO 2, 8 have been

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TiO 2 -supported transition metal oxides (Mn, Cr, and Cu) for the SCR of NO with NH 3 have been synthesized by wet impregnation. The adsorption and coadsorption of NH 3 , NO, and O 2 , in conjunction with in situ FT-IR spectroscopy, was used to elucidate the reaction mechanism as the samples were heated from 323 to 673 K. While Cr was the only transition metal that generated significant amounts of Brønsted acidity, strong Lewis acid sites were present over all of the materials. The peak strength corresponding to the δ s (NH 3 ) coordinated to Lewis acid sites decreased in the following order: Ti > Mn > Cr ∼ Cu. Similarly, the peak strength corresponding to the δ as (NH 3 ) coordinated to Lewis acid sites decreased as follows: Mn > Cr ∼ Cu. Exposing the catalysts to oxygen before the introduction of NO did not impact the adsorption of NO as nitrates on the catalysts, suggesting that labile lattice oxygen plays an important role in the formation of nitrates. Three types of nitrates were observed after the adsorption of NO. Monodentate and bidentate nitrates formed on the surface of all the materials tested, while bridged nitrates only formed on CrO x /TiO 2 . The in situ FTIR data collected resulted in the development of a reaction mechanism for MnO x /TiO 2 . A combination of moderately strong monodentate and bidentate nitrate species, along with a split in the symmetric deformation of NH 3 coordinated to Lewis acid sites, appear to be important for high activity and selectivity. The peak resulting from the vibrational mode of ammonia adsorbed on Lewis acid sites, which is located at ∼1170 cm -1 , is believed to be important in facilitating hydrogen abstraction to form amide species that react with bidentate nitrates (1620 cm -1 ). It is proposed that the reaction mechanism proceeds through the formation of nitrosamide and azoxy species, which most likely possess lifetimes as reaction intermediates that are too brief for detection. In contrast to MnO x /TiO 2 , the apparent participation of Brønsted acid sites for CrO x /TiO 2 suggests that a different reaction pathway is involved for this catalyst.

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