Catalytic wet air oxidation of pentachlorophenol over Ru/ZrO2 and Ru/ZrSiO2 catalysts

ZrSiO2 and ZrO2 supports loaded with active component Ru were unprecedentedly evaluated in catalytic wet air oxidation reaction of pentachlorophenol (PCP). The study results showed that the specific surface area of ZrSiO2 which was prepared by high temperature aging method was much larger than that of ZrO2, and it performed a better catalytic activity in catalytic wet air oxidation after being loaded with Ru. When the initial concentration of PCP was 125 mg L−1, PCP conversion reached 92% after 90 min under the low temperature and pressure conditions of 180 °C and 0.1 MPa oxygen partial pressure. PCP conversion was increased by raising reaction temperature, increasing oxygen partial pressure, reducing the initial concentration of PCP and prolonging reaction time. The kinetics study of PCP in catalytic wet air oxidation showed that the catalytic wet air oxidation reaction of PCP obeyed first order kinetic model and its Arrhenius activation energy was 96.98 kJ mol−1. The main intermediates of PCP in CWAO were acetic acid, oxalic acid and chlorine ion.

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► This is the first report about the PCP treatment in CWAO.
► The high specific surface area of ZrO2 is caused not by the high temperature but by the SiO2.
► The reaction kinetics of PCP in CWAO was studied.
► Degradation pathways of PCP in CWAO were studied.