Promotion role of some metals (Cu, Ag) in the side chain alkylation of toluene by methanol

Elucidating the Distribution and Speciation of Boron and Cesium in BCsX Zeolite Catalysts for Styrene Production

“…Catalytic tests (Figure ) conducted over appropriately sized sieve fractions of the materials prepared in powder form provided evidence of the preferential side‐chain alkylation of toluene toward ethylbenzene over CsX (selectivity >80 %), which was largely shifted toward styrene upon addition of the boron modifier . The distribution of alkylated products obtained over CsX g strongly resembled that over CsX.…”

“…A survey of the open literature on the synthetic routes and testing procedures more commonly reported for BCsX zeolites found that preparation procedures usually included a drying step at temperatures around 373 K (herein 383 K in air) after the incorporation of the boron‐containing precursor . Because boric acid (frequently used as the source) dehydrates into boric oxide at about 363 K, which, in turn, melts at temperatures from 573 to 723 K, boric oxide is expected to be the predominant species in the dried, fresh catalyst.…”

“…Because boric acid (frequently used as the source) dehydrates into boric oxide at about 363 K, which, in turn, melts at temperatures from 573 to 723 K, boric oxide is expected to be the predominant species in the dried, fresh catalyst. Nonetheless, prior to the reaction, the catalyst is typically treated in situ at temperatures between 723 and 773 K, at which boric oxide should be a liquid. With this in mind, the chemical state of boron species close to the surface of BCsX was studied by XPS prior to and after calcination (773°K, N 2 , 2 h).…”

Styrene from Toluene by Side Chain Alkylation over a Novel Solid Acid-base Catalyst

“…When these alkali compounds were supported on zeolites, they demonstrated the yield (ethylbenzene C styrene) of about 20% and styrene selectivity of about 10% (Serra et al, 2003;Palomares et al, 1998;Wieland et al, 1998). Some other studies found that the selectivity to styrene could be improved by adding B, P, Cu, or Ag to these basic zeolites (Lacroix et al, 1984). Also, small quantities of alkali-hydroxide particles entrapped within the alfa cavities of faujasite, strongly increase the alkylation in the side-chain of alkylaromatics (Hathaway and Davis, 1989;Engelhard et al, 1987).…”

Preparation of Oxide, Sulfide and Other Chalcogenide Clusters in Molecular Sieves

“…A first hint at the usefulness of such procedures was published in 1984: Lacroix et al reported that cesium-exchanged zeolite X is more active in the side-chain alkylation of toluene with methanol when left unwashed after the cation exchange [1]. Hathaway and Davis [2][3][4] carried out further systematic studies on the preparation of intrazeolitic oxide clusters with basic properties.…”