Abstract
Post-synthesis modification of silicalite-1 (MFI) with solutions of ammonium compounds (NH4F, NH4Cl, NH4NO3, NH4OH) without any additional alkaline agent followed by further thermal treatment appeared a new, facile, and cheap method to generate the acidic sites in starting material. The number and strength of resulting acid sites depend on the nature of anion in the applied ammonium salt. Used procedure resulted in partial removal of external silanol groups and in the formation of acidic internal isolated as well as hydrogen bonded OH groups (e.g. silanol nests). The novel acidic sites show a high catalytic activity for acetalization of glycerol with acetone and high selectivity towards 2,2-dimethyl-1,3-dioxolane-4-methanol (solketal). The modified silicalite-1 indicates also high stability with time on stream. The proposed reaction mechanism considers a combined contribution of both Lewis and very weak Brønsted acid sites.
Sign-in/Register to access full text options 
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.
