The infra-red spectrum of pyridine adsorbed on titanium dioxide was measured by means of a diffuse reflectance type of FT-IR, and found that pyridine coordinately bonded to the Lewis acid sites of titanium dioxide.
In the same way as pyridine, propylene oxide was adsorbed on titanium dioxide. When propylene oxide was adsorbed on titanium dioxide at 50°C, OH groups of titanium dioxide were decreased. And then, epoxide ring of adsorbed propylene oxide was opened and chemisorbed carbonyl was formed as temperature raised.
On the other hand, isomerization of propylene oxide was occurred and propionaldehyde and acetone were formed over titanium dioxide by a pulse reactor method at 300°C.
Close agreement between the result of infra-red spectra and pulse reactor method was obtained, and isomerization mechanism of propylene oxide was clarified.
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