The solubility of ammonium tungstate in a special hydrothermal condition is exploited to synthesize uniform microspheres of Ce-Cu-W-O oxides.Compared to their W-undoped counterparts,they possess more Ce^3+ and oxygen ...The solubility of ammonium tungstate in a special hydrothermal condition is exploited to synthesize uniform microspheres of Ce-Cu-W-O oxides.Compared to their W-undoped counterparts,they possess more Ce^3+ and oxygen vacancies,thereby promoting oxygen mobility.The formed rich WO3 surface can effectively provide acid sites,which is helpful for adsorption of vinyl chloride and interrupting the C-Cl bond.In addition,the presence of WO3 induces the formation of finer CuO nanoparticles with respect to the traditional coprecipitation method,thereby resulting in a better reducibility.Benefiting from both the enhanced acidity and reducibility,the Ce-Cu-W-O microspheres deliver excellent low-temperature vinyl chloride oxidation activity(a reaction rate of 2.01×10^-7 mol/(gcat·s)at 250℃)and high HCl selectivity.Moreover,subtle deactivation occurs after the three cycling activity tests,and a stable vinyl chloride conversion as well as mineralization are observed during the 72-h durability test at 300℃,which demonstrates good thermal stability.Our strategy can provide new insights into the design and synthesis of metal oxides for catalytic oxidation of chlorinated volatile organic compounds.展开更多
文摘The solubility of ammonium tungstate in a special hydrothermal condition is exploited to synthesize uniform microspheres of Ce-Cu-W-O oxides.Compared to their W-undoped counterparts,they possess more Ce^3+ and oxygen vacancies,thereby promoting oxygen mobility.The formed rich WO3 surface can effectively provide acid sites,which is helpful for adsorption of vinyl chloride and interrupting the C-Cl bond.In addition,the presence of WO3 induces the formation of finer CuO nanoparticles with respect to the traditional coprecipitation method,thereby resulting in a better reducibility.Benefiting from both the enhanced acidity and reducibility,the Ce-Cu-W-O microspheres deliver excellent low-temperature vinyl chloride oxidation activity(a reaction rate of 2.01×10^-7 mol/(gcat·s)at 250℃)and high HCl selectivity.Moreover,subtle deactivation occurs after the three cycling activity tests,and a stable vinyl chloride conversion as well as mineralization are observed during the 72-h durability test at 300℃,which demonstrates good thermal stability.Our strategy can provide new insights into the design and synthesis of metal oxides for catalytic oxidation of chlorinated volatile organic compounds.
