Highly efficient and stable hydrodechlorination of chlorophenols in a flow Pd–Ce/SiO2/Ni foam reactor

Abstract

The foam reactor shows attractive potential for employment in fast and often diffusion limited processes such as hydrodechlorination (HDC). Three Pd-based Ni foam reactors were developed for HDC of chlorophenols (CPs) in flow. The presence of SiO₂ coating and CeO₂ in the Pd–Ce/SiO₂/Ni foam reactor leads to the improvement of the catalytic surface area and promotes active Pd dispersion. The highly oxidizing nature of Pd, attributed to the strong interaction between Ce and Pd, was observed in this foam reactor. The kinetic study illustrated that the Pd–Ce/SiO₂/Ni foam reactor exhibited the fastest kinetics and lowest apparent activation energy. A broad series of CPs were almost thoroughly degraded (conversion >99% and outlet concentration <1 ppm) with a short cycle time of 60 s. In addition, excellent long-term catalytic stability for HDC in real water was presented by the Pd–Ce/SiO₂/Ni foam reactor, making it a promising candidate for application of HDC in water treatment.