Promoted effect of alkalization on the catalytic performance of Rh/alk-Ti3C2X2 (X=O, F) for the hydrodechlorination of chlorophenols in base-free aqueous medium

Exploring MXenes as supports for synthesis of highly efficient catalysts are extremely important for hydrodechlorination of chlorophenols because of the acute toxicity and strong potential bioaccumulation of chlorophenols. We reported a facile strategy to synthesize Rh nanoparticles deposited on 2D alk-Ti3C2X2 (X= O, F) (alk-Ti3C2X2 for short) MXene, which was prepared through the removal of the Al layers of Ti3AlC2 and post-treatment by alkalization. Modifying the Ti3C2X2 support by alkalization triggered the substitution of surface fluorine groups with surface oxygen species. The changes in the surface chemistry of alk-Ti3C2X2 effectively prevented particle aggregation to form well-dispersed Rh nanoparticles in small sizes with relative high metal dispersion, thereafter improving the hydrogen uptake capacity of the catalyst. Consequently, the Rh/alk-Ti3C2X2 catalyst significantly enhanced the catalytic performance for the HDC reaction, which could be assigned to the large number of active components from small Rh nanoparticles. This strategy provides a basis for investigating the use of MXenes as supports to synthesize well-defined metal nanoparticles in 2D layered structures for potential applications. (C) 2017 Elsevier B.V. All rights reserved.