One-step controllable strategy for synthesizing hierarchical Fe-MFI/MCM-41 composites using CTAB as a dual-functional template

Hierarchical Fe-doped MFI/MCM-41 composites (Fe-HMZs) were one-pot hydrothermal synthesized by partial transformation strategy using conventional CTAB as a dual-functional template. The hierarchical Fe-doped MFI/MCM-41 composites possess ordered mesopores and crystallized MFI structure. The effect of addition amount of NaOH and CTAB as well as the type of the alkali source on the formation of hierarchical Fe-MFI/MCM-41 composites have been investigated in detail. In addition, the temperature-gradient treatment plays the vital roles in the formation of MFI and the possible formation mechanism has been proposed. The obtained hierarchical Fe-HMZ-40 sample exhibits outstanding catalytic performance for phenol hydroxylation and 48% of phenol conversion as well as 89% of dihydroxybenzene selectivity could be achieved, which are ascribed to the more accessible active sites endowed by the significant diffusion ability of ordered mesopores. Compared with Fe-MCM-41 sample, the hydrothermal stability is improved because of the presence of MFI structure.