Development of a next generation cracking catalyst based on analysis of acidic property and structure of active site on USY zeolite

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Properties of Bronsted and Lewis acid sites and number of Bronsted acid strength of OH groups on various zeolites became able to be measured by developing the ammonia IRMS-TPD method. Treatment of USY zeolite with an EDTA-salt with neutral property increased strong Bronsted aridity. The presence of strained tetra-coordinated and extraframework Al species on EDTA-USY, this is considered to be the origin of the strong Bronsted acidity. This was identified by 16T NMR. By the IRMS-TPD, the string acidity of OH was directly observed, and this was the first direct observation of active site for alkane cracking on USY.Applying with quantum calculation, it was clarified that extraframework AlOH coordinated at the window of hexagonal prism enhanced the Bronsted acidity of adjacent OH. This is the origin of cracking activity of USY. At the same position, Ca etc. also enhanced the acidity.Thus the structure of alkane cracking site was clarified. Application of these catalysts to octane cracking showed a potential activity for next generation catalyst.In addition, acidic property of a mesoporous zeolite, which was expected to have a potential for cracking of heavy oil, has been analyzed for the first time. WO_3/ZrO_2 was also analyzed. A method for analysis of the adsorption heat of aromatic molecule on zeolite was developed.