Seed-assisted synthesis of high silica ZSM-35 through interface-induced growth over MCM-49 seeds

• High-silica ZSM-35 is synthesized assisted by non-calcined MCM-49 seeds.
• This is the first exception that without CBUs contained in both of the seeds and products.
• High solid yields of 65–85% have been achieved, which are attractive for industrial applications.
• It is estimated that the ZSM-35 might have grown over MCM-49 seeds through interface-induction.
• H–ZSM-35 shows excellent stability and high selectivity towards methyl acetate (MA) in DME carbonylation.

High-silica ZSM-35 has been successfully synthesized by adding non-calcined MCM-49 seeds to the initial gel without the help of organic structure-directing agents (OSDAs). This is the first report of seed-assisted synthesis without the common composite building units (CBUs) contained in the seeds and products. High solid yields of 65–85% have been achieved, which are the highest values ever reported for the seed-assisted synthesis. Alkaline treatment and hyperpolarized 129Xe NMR are employed to study the ZSM-35 products, and an interface-induced growth mechanism is proposed, in which ZSM-35 grows over partially dissolved MCM-49 through interface connection. It is supposed that similarity in the local atomic connection between the seeds and target zeolites, even without the common CBUs, would have the possibility to lead to a successful synthesis. The catalytic performance of H-ZSM-35 is tested in the dimethyl ether (DME) carbonylation, which shows excellent stability and high selectivity towards methyl acetate (MA).

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