Abstract
Catalytic performance and availability of supported heteropoly acid under vapor-phase conditions were studied through alkylation of benzene with ethylene, esterification of acetic acid with ethanol, and dehydration of 2-propanol as model reactions. These reactions differ from each other in terms of the affinity of reaction substrate for heteropoly acid. Heteropolytungstic acid exhibited high catalytic activity and selectivity when it was loaded on silica gel or on activated carbon. In every reaction, there was observed a ceiling of catalytic activity at a certain content of heteropoly acid (ca. 15–25 wt%). The results of XRD and TPD measurements on supported heteropoly acid suggest that the reactions which are operated at more than 150 °C proceed principally on the surface, or at most in the surface layers, of the heteropoly acid crystallites dispersed on support. Supported heteropoly acid appears to excel silica-alumina, supported phosphoric acid, and acidic zeolites in the catalytic capability particularly for those reactions which are carried out at relatively low temperatures (less than 200 °C) or involve water as a reactant or a product.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
