Ferrierite nanosheets with preferential Al locations as catalysts for carbonylation of dimethyl ether

Enriching Al atoms in T2 and T4 sites of FER zeolite is decisive for achieving high catalytic activity in the carbonylation reaction of dimethyl ether (DME). Regulating the spatial position of Al atoms in targeted framework sites remains to be a great challenge during the synthesis of FER zeolite. The FER nanosheets with preferential Al-sitting in T2 and T4 sites were successfully synthesized with the assistance of cetyltrimethylammonium bromide (CTAB). The effect of CTAB on the morphology and Al distribution has been investigated in detail. CTAB mostly adsorbed on external surface serving as growth inhibitors, which resulted in nanosheet morphology and changed the length ratio along the b-axis to c-axis of the crystals. A minor portion of CTAB located in the channels may favor the spatial Al location in T2 and T4 sites, indicated by the results from 27Al MAS NMR spectra. The FER nanosheets exhibited improved DME conversion, stability, space-time yield (STY), and lifetime compared to conventional FER in DME carbonylation reaction.