Effective catalytic hydrodechlorination removal of chloroanisole odorants in water using palladium catalyst confined in zeolite Y

Chloroanisoles is a class of odorous pollutants commonly identified in drinking water . In the present study, we confined noble metal palladium (Pd) in the micropores of zeolite Y ( ie -Pd@Y) using an ion exchange method, and applied it for the catalytic hydrodechlorination removal of chloroanisoles (represented by 2,4,6-trichloroanisole/TCA) in water. Pd supported on zeolite Y surface ( im -Pd/Y, prepared by conventional impregnation method) was used as the benchmarking catalyst. The characterization results revealed that ie -Pd@Y had smaller Pd particle size and higher Pd n+ /Pd 0 ratio than im -Pd/Y. The catalytic hydrodechlorination of TCA followed a concerted dechlorination pathway and the Langmuir-Hinshelwood model. The ie -Pd@Y catalysts with different Pd loadings exhibit excellent catalytic activities with more than 95% of TCA removed within 30 min, which is far superior to the im -Pd/Y catalysts (27–70%). Moreover, due to the confinement effect of zeolite Y, ie -Pd@Y displayed enhanced catalytic stability as compared with im -Pd/Y. The initial activity of ie -Pd@Y was more than 20 times higher than that of im -Pd/Y after five reaction cycles. Additionally, with the assistance of sieving effect, ie -Pd@Y displayed much stronger capability against the interference from dissolved organic matter than im -Pd/Y. The present results demonstrate that the confined catalysts ie -Pd@Y can be applied in liquid phase catalytic hydrogenation to effectively eliminate halogenated odorants in waters.