Abstract
Monochloroacetic acid(MCAA)is identified as a highly carcinogenic disinfection by-product in chlori-nated drinking water.In this study,a series of CeO2-sup-ported Pd catalysts(Pd/MCeO2)were synthesized through one-step calcination of Pd-loaded Ce-UiO-66-BDC(Ce-MOF),and the liquid-phase catalytic hydrodechlorination of MCAA was explored using these catalysts.For com-parison,Pd/CeO2 catalysts were additionally synthesized using the conventional impregnation method.The charac-terization results reveal that the catalysts exhibit strong metal-support interaction,leading to high Pd dispersion and Pdn+content.Additionally,the calcination temperature significantly influences catalytic performance,with the catalyst calcined at 500 ℃(Pd/MCeO2-500)demonstrat-ing the highest catalytic activity and achieving complete dechlorination of MCAA within 50 min.Furthermore,it is found that the catalytic MCAA hydrodechlorination using the catalysts adheres to the Langmuir-Hinshelwood model.Accordingly,low reaction pH is favorable for the catalytic hydrodechlorination of MCAA,enhancing MCAA adsorption on the catalyst surface due to the electrostatic interaction between MCAA and the catalyst surface.The-oretical results suggest that the presence of Pdn+efficiently facilitates MCAA adsorption and C-Cl cleavage,thus significantly enhancing the liquid-phase catalytic hydrodechlorination.
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