Catalytic oxidation of vinyl chloride emissions over Co-Ce composite oxide catalysts

A series of Co-Ce composite oxide catalysts with different molar ratio were prepared by the citrate sol-gel method and evaluated for the catalytic oxidation of vinyl chloride present in air, which was selected as a model reaction for chlorinated VOCs abatement from industrial exhaust. Numerous of characterization techniques including XRD, N-2 sorption, Raman, H-2-TPR, O-2-TPD, NH3-TPD, XPS and HR-TEM were used to evaluate the influence of the physicochemical properties on the catalytic oxidation of 1000 ppm of vinyl chloride at a GHSV of 15,000 h(-1). The presence of cerium in the cobalt oxides modified the redox properties and the chemical states of the Co-Ce composite oxide catalysts, increasing the presence of Co2+ species, the oxygen vacancies, and the oxygen mobility. Among the Co-Ce composite oxide catalysts, the one with a Co/(Ce + Co) molar ratio at 0.7 presented the highest catalytic activity and stability for the oxidation of vinyl chloride, which was related to the synergetic effect derived from the high reactivity on Co2+ sites and its further oxidation by surface active oxygen species. (C) 2017 Elsevier B.V. All rights reserved.