Synthesis and characterization of chromia-pillared layered tetratitanate

The first chromia-pillared layered tetratitanate was prepared by the reacti on of layered tetramethylammonium tetratitanate with chromium(III) acetate [Cr(OAc)(3)] aqueous solution and subsequent calcination of the resultant s olid product in air at 400 degrees C. The obtained chromia-pillared layered tetratitanate has an interlayer distance of 1.06 nm and a high thermal sta bility up to 600 degrees C. It was also found that calcination in N-2 led t o the chromia-pillared layered tetratitanate with relatively higher Brunaue r-Emmett-Teller (BET) specific surface area (93.9 m(2).g(-1)) and smaller a verage pore diameter (4.44 nm) than that in air (82.0 m(2).g(-1), 7.61 nm). Both Bronsted and Lewis acid sites (mainly Lewis type) are present on the chromia-pillared layered tetratitanate (500 degrees C, N-2, 8 h) and strong enough to still remain a small proportion of pyridine upon outgassing at 2 50 degrees C. Moreover, ammonia temperature-programmmed desorption (NH3-TPD ) result showed that there were three NH3 desorption peaks at 160, 200 and 315 degrees C, respectively. The corresponding; acid amount is 41.3, 73.9 a nd 290.7 mu mol.g(-1). The total acid amount is 405.9 mu mol.g(-1).