A CTAB assisted synthesis strategy to control the size and performance of FER zeolites is developed.

A series of ZSM-35 zeolites with different alkaline treatment degrees were prepared. The precise effects of alkaline treatment on composition, morphology, porosity, transportation and acidity of the samples were characterized by means of multiple techniques including N₂ sorption, transmission electron microscopy (TEM), intelligent gravimetric analyzer (IGA) and Fourier transform infrared spectroscopy (FTIR). ZSM-35 after moderate alkaline treatment exhibited enhanced carbonylation activity compared with the parent sample. As revealed by the N₂ adsorption and TEM results, alkaline treatment could induce the deaggregation of ZSM-35 clusters and remove the amorphous debris on the surface of ZSM-35 platelets. Furthermore, an improved diffusion behavior of the dimethyl ether reactant molecule was observed on the alkali-treated sample from IGA experiments which directly led to the better catalytic performance for the carbonylation of the dimethyl ether with carbon monoxide. Mesoporosity created by severe alkaline leaching does not enhance the catalytic properties of ZSM-35 in dimethyl ether carbonylation reaction. Especially, a decrease in reaction stability was observed due to the limitation effect of carbonaceous deposit formation.

Zeolite beta, an important catalytic material widely applied in the petrochemical field, is typically prepared under hydrothermal conditions. However, it usually suffers from the drawback of relatively long crystallization time. Herein, we show that the crystallization rate of zeolite beta can be accelerated by a factor of as much as about nine via the addition of the low-toxic and cost-effective pentacyclic lactam N-methyl-2-pyrrolidone (NMP) as a ‘promoter’. Using characterization techniques, we demonstrate that the pentacyclic lactam induces the fast formation of secondary building units (SBUs) and enhances the formation rate of the activated TEA⁺ species responsible for the nucleation of beta crystals. More importantly, the as-synthesized beta exhibited high product yield (above 85 wt%) and good performance in the direct amination of isobutene (i-C₄H₈) to tert-butylamine reaction.

MCM-49 zeolite with a three-dimensional MWW framework was directly synthesized using low-toxicity and cost-effective cyclohexylamine (CHA) as an organic structure-directing agent under hydrothermal conditions.