The effect of gold loading on the catalytic oxidation activity of CeO2/H2O2 system

摘要

There are great interests in redox catalytic applications for CeO2 due to its rich oxygen vacancies and low redox potential between Ce3+ and Ce4+.In environmental remediation studies,along with the catalytic wet oxidation,Fenton-like reactions catalyzed by cerium salt and CeO2 in the presence of H2O2 have also been reported for the removal of organic pollutants.The reaction of cerium and H2O2 underwent the cycle of Ce4+/Ce3+ with the generation of superoxide and hydroxyl radicals.However,the CeO2-based Fenton-like reaction was spotted going on as a localized surface reaction rather than a supemxide/hydroxyl radical-attack reaction in neutral water in our previous studies.It was verified that the peroxide-like species (O22-) formed on the surface of CeO2 in the CeO2/H2O2 system are relatively chemically stable and can only degrade substances adsorbed on the surface of CeO2 via an intermolecular rearrangement.