Analysis and interpretation of acidic nature of aluminosilicates

Aluminosilicate solid acid catalysts, especially zeolites, have been widely utilized in petroleum refinery and environmentally benign chemical processes. The acidic property of aluminosilicates has been a subject of advanced studies. Recently an ammonia IRMS-TPD (infrared/mass spectroscopy temperature-programmed desorption) method, an application of operando technique, has been developed to quantify the number and strength distribution of each of Brønsted and Lewis sites on a solid. With an aid of quantum chemistry, relationships among the composition, structure and acidic property are being unveiled to totally understand the chemistry of SiOHAl unit in the aluminosilicates.