Hydrophobic Zeolite Containing Titania Particles as Wettability-Selective Catalyst for Formaldehyde Removal

This work delineates a concept of wettability-selective catalyst, which is realized by functionalizing a metal oxide catalyst within a zeolite sheath with controllable wettability. We synthesized such zeolite sheaths by anchoring organic groups (e.g., -CH 3 ) into a faujasite framework during the crystallization, achieving hydrophobic micropores for selective capture of organic compounds but hindering water diffusion. Further fixation of TiO 2 particles within these zeolite crystals resulted in core–shell catalysts denoted as TiO 2 @HP-zeolite, which combined the functions of both wettability selectivity for the zeolite sheath and photocatalytic activity for the TiO 2 . Owing to the synergism of these features, TiO 2 @HP-zeolite displayed superior performances in complete removal of wet formaldehyde in a long-period continuous test under irradiation of sunlight frequencies, outperforming the conventional catalysts with poor water tolerance.