Abstract
Hydrothermally synthesized H-[Al,B]-MWW zeolite was dealuminated with oxalic, nitric and citric acids. The obtained samples were characterized with XRD, ICP-AES, FT-IR, NH3-TPD, pyridine-adsorption IR, 27Al MAS NMR techniques and nitrogen sorption experiment. Citric acid mainly removed the acid sites located on the external surface pockets with small amounts of extraframework Al species retained in the interlayer void space, while nitric acid leached both the internal (sinusoidal channels and supercages) and the external surface (side pockets) acid sites although significant amounts of extraframework Al species were generated in the sinusoidal channels. As for the oxalic acid, it primarily eliminated the acid sites in the supercages and side pockets without generation of considerable amounts of extraframework Al species in the internal channels, consequently greatly increasing the catalytic stability of the sample in methylation of ethene by methanol. The sample dealuminated with oxalic acid for 24 h showed a catalytic life of 300 h as a result of a reduction in coking rate.
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.
