Performance of mesoporous CeO_(2)-Cr_(2)O_(3) mixed metal oxides applied to benzene catalytic combustion

In this paper,a hydrothermal method was used to prepare(Ce,Cr)-MOF with different Ce/Cr molar ratios and then a series of CeO_(2)-Cr_(2)O_(3) mixed metal oxides(CeCr-MMO)with mesoporous structure were prepared by thermal decomposition of these MOFs at different temperatures.After a series of characterization techniques were applied to test the physicochemical properties of the materials,it is found that thermal decomposition temperature(TDT)and Ce/Cr molar ratios have important effects on the structure and performance of CeCr-MMO.As the TDT reaches 400℃ and above,(Ce,Cr)-MOF can be completely decomposed to form CeCr-MMO.The catalyst with Ce/Cr molar ratio of 4:1 has the highest catalytic activity,which can completely degrade benzene at 230℃.It is concluded that the interaction between CeO_(2) and Cr_(2)O_(3) is helpful for increasing the concentration of Ce^(3+),Cr^(6+) and lattice oxygen species(OLatt)on the catalyst surface,thus improving the catalytic performance.Moreover,CeCr(4:1)-MMO-400 shows excellent durability against the presence of chlorobenzene and H2O during 100 h continuous reaction.