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MnxCe1-xO2(x:0.3–0.9)prepared by Pechini method was used as a catalyst for the thermal catalytic oxidation of formaldehyde(HCHO).At x=0.3 and 0.5,most of the manganese was incorporated in the fluorite structure of Ce O2to form a solid solution.The catalytic activity was best at x=0.5,at which the temperature of 100%removal rate is the lowest(270°C).The temperature for 100%removal of HCHO oxidation is reduced by approximately 40°C by loading 5 wt.%Cu Oxinto Mn0.5Ce0.5O2.With ozone catalytic oxidation,HCHO(61 ppm)in gas stream was completely oxidized by adding 506 ppm O3over Mn0.5Ce0.5O2catalyst with a GHSV(gas hourly space velocity)of 10,000 hr-1at 25°C.The effect of the molar ratio of O3to HCHO was also investigated.As O3/HCHO ratio was increased from 3 to 8,the removal efficiency of HCHO was increased from 83.3%to 100%.With O3/HCHO ratio of 8,the mineralization efficiency of HCHO to CO2was 86.1%.At 25°C,the p-type oxide semiconductor(Mn0.5Ce0.5O2)exhibited an excellent ozone decomposition efficiency of 99.2%,which significantly exceeded that of n-type oxide semiconductors such as Ti O2,which had a low ozone decomposition efficiency(9.81%).At a GHSV of 10,000 hr-1,[O3]/[HCHO]=3 and temperature of 25°C,a high HCHO removal efficiency(≥81.2%)was maintained throughout the durability test of 80 hr,indicating the long-term stability of the catalyst for HCHO removal.
MnxCe1-xO2 (x: 0.3-0.9) prepared by Pechini method was used as a catalyst for the thermal catalytic oxidation of formaldehyde (HCHO) .At x = 0.3 and 0.5, most of the manganese was incorporated in the fluorite structure of Ce O2to form a solid solution. The catalytic activity was best at x = 0.5, at which the temperature of 100% removal rate is the lowest (270 ° C). The temperature for 100% removal of HCHO oxidation is reduced by approximately 40 ° C by loading 5 wt.% Cu Oxinto Mn0.5Ce0.5O2.With ozone catalytic oxidation, HCHO (61 ppm) in gas stream was completely oxidized by adding 506 ppm O3 over Mn0.5Ce0.5 O2 catalyst with a GHSV (gas hourly space velocity) of 10,000 hr-1at 25 ° C. The effect of the molar ratio of O3to HCHO was also investigated. As O3 / HCHO was increased from 3 to 8, the removal efficiency of HCHO was increased from 83.3% to 100% .With O3 / HCHO ratio of 8, the mineralization efficiency of HCHO to CO2 was 86.1% .At 25 ° C, the p-type oxide semiconductor (Mn0.5Ce0.5O2) showed an excellent ozone dec At a GHSV of 10,000 hr-1, [O3] / [HCHO] = 3 and temperature of 25 ° C, a high HCHO removal efficiency (≥81.2%) was maintained throughout the durability test of 80 hr, indicating the long-term stability of the catalyst for HCHO removal.