Acidity Control and Catalysis of Pentasil Zeolites

Influence of Na+ on the synthesis of silicalite-1 catalysts for use in the vapor phase Beckmann rearrangement of cyclohexanone oxime

“…So, catalysts with larger crystal sizes deactivate much faster. These results are in accordance with the results of Sato [2] with ZSM-5 catalysts, which also deactivated faster with larger particles.…”

“…Addition of Na + to ZSM-5 or TiO 2 leads to an increase in crystal sizes and affects the morphology of the cystals [35][36][37]. In studying the ZSM-5 catalyzed vapor phase Beckmann rearrangement of cyclohexanone oxime, Sato [2] found that larger particles resulted in higher external surface areas of ZSM-5, and deactivated more quickly in the reaction. Up until now, the effects of Na + on the synthesis of S-1 (its crystal size, morphology, catalytic performance and especially its stability, in the vapor phase Beckmann rearrangement of cyclohexanone oxime) have not been reported.…”

“…ε-Caprolactam is a large volume chemical commodity used as a monomer in the production of Nylon-6 [1][2][3]. The current liquid phase Beckmann rearrangement route has several disadvantages such as corrosion of the reactor and production of a large amount of ammonium sulfate byproduct [3].…”

Rationalising the role of solid-acid sites in the design of versatile single-site heterogeneous catalysts for targeted acid-catalysed transformations

“…31 Earlier studies have indicated that strong Brønsted acid sites in zeolites play a crucial role in catalyzing the Beckmann rearrangement, by protonating the oxime. 15,[41][42][43] However, parallel studies 44 have indicated that the presence of these strong-acid sites favor the formation of byproducts, thereby decreasing the overall yield of 3-caprolactam. 45 In more recent studies, it has been suggested that weaker Brønsted acid sites and silanol groups or silanol nests play a pivotal role in modulating the selectivity in the Beckmann rearrangement of cyclohexanone oxime.…”

Direct Synthesis of Functional Zeolitic Materials

“…The catalytic activity of silicoaluminate MFI nanosheets was also studied in other interesting industrial catalytic applications, such as gas-phase Beckmann rearrangement [157]. The conversion of cyclohexanone oxime to ε-caprolactama is a remarkable industrial reaction for the production of Nylon-6 [158]. This reaction is industrially performed by microporous MFI acid catalyst.…”