Biotemplate Fabrication of Hollow Tubular CeSrTiO with Regulable Surface Acidity and Oxygen Mobility for Efficient Destruction of Chlorobenzene: Intrinsic Synergy Effect and Reaction Mechanism.

Developing economic and applicable catalysts with elegant chlorine resistance and organic byproduct inhibition capability is of great significance for chlorinated volatile organic compounds (Cl-VOCs) eco-friendly purification. Here, ternary CeSrTiO catalysts with tunable surface acidity and oxygen species mobility were creatively fabricated using the hollow tubular-structured fruit hair of Platanus (FHP; a widespread greenery waste) as the scaffolding biotemplate. It is shown that the oxygen vacancy (O) triggered by the presence of Ce can optimize the synergy between the Lewis acid sites (LAS) and Brønsted acid sites (BAS). High concentration of O and BAS promotes the C-Cl cleavage of chlorobenzene (CB) and accelerates the desorption of Cl radicals as inorganic chlorine. Simultaneously, the strong electron transfer within Ti-Ce-Sr linkage increases the acidity of LAS, resulting in the superior reducibility of CeSrTiO and facilitating the deep oxidation of dechlorination intermediates. Additionally, the spatial confinement of the tubular structure remarkably accelerates the CB flow rate and reduces the residence time of byproducts over the prepared catalysts. Owing to these, CB can be efficiently destructed over CeSrTiO with selectivity of CO and inorganic chlorine dramatically enhanced, respectively, approximately 16 and 21 times at 275 °C compared to those of pure SrTiO. The present work provides a feasible and promising strategy for engineering efficient catalysts for heterogeneous thermocatalytic reactions for industrial-scale Cl-CVOC destruction.