Remarkably efficient Pt/CeO2-Al2O3 catalyst for catalytic hydrodeiodination of monoiodoacetic acid: Synergistic effect of Al2O3 and CeO2.

Monoiodoacetic acid (MIAA) is one of the highly toxic halogenated disinfection by-products, which is formed during water disinfection processes. Catalytic hydrogenation with supported noble metal catalyst is a green and effective technique for the transformation of halogenated pollutant, but its activity still needs to be identified. In this study, Pt nanoparticles were supported on CeO2 modified γ-Al2O3 (Pt/CeO2-Al2O3) by chemical deposition method and the synergistic effect of Al2O3 and CeO2 on catalytic hydrodeiodination (HDI) of MIAA was systematically studied. Characterizations revealed that Pt dispersion could be improved by the introduced CeO2 through the formation of Ce-O-Pt bond and MIAA adsorption could be facilitated by high Zeta potential of Al2O3 component. Furthermore, optimal Ptn+/Pt0 could be obtained by adjusting CeO2 deposition amount on Al2O3, which could effectively facilitate the activation of C-I bond. Therefore, Pt/CeO2-Al2O3 exhibited remarkable catalytic activities and TOF values compared with those of Pt/CeO2 and Pt/Al2O3. Through detailed kinetic experiments and characterization, the extraordinary catalytic performance of Pt/CeO2-Al2O3 can be attributed to the abundant Pt sites as well as the synergistic effect between CeO2 and Al2O3.