Graduate Institute of Environmental Engineering, National Central University, Chungli 32001, Taiwan, Chinese Taipei.
Industrial Technology Research Institute, Hsinchu 31040, Taiwan, Chinese Taipei.
J Environ Sci (China). 2014 Dec 1;26(12):2546-53. doi: 10.1016/j.jes.2014.05.030. Epub 2014 Oct 22.
Mn(x)Ce(1)-(x)O(2) (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 CeO(2) to 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 5wt.% CuO(x) into Mn(0.5)Ce(0.5)O(2). With ozone catalytic oxidation, HCHO (61 ppm) in gas stream was completely oxidized by adding 506 ppm O₃over Mn(0.5)Ce(0.5)O(2) catalyst with a GHSV (gas hourly space velocity) of 10,000 hr⁻¹ at 25°C. The effect of the molar ratio of O(3) to HCHO was also investigated. As O(3)/HCHO ratio was increased from 3 to 8, the removal efficiency of HCHO was increased from 83.3% to 100%. With O(3)/HCHO ratio of 8, the mineralization efficiency of HCHO to CO(2) was 86.1%. At 25°C, the p-type oxide semiconductor (Mn(0.5)Ce(0.5)O(2)) exhibited an excellent ozone decomposition efficiency of 99.2%, which significantly exceeded that of n-type oxide semiconductors such as TiO(2), which had a low ozone decomposition efficiency (9.81%). At a GHSV of 10,000 hr⁻¹, [O(3)]/[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.
采用柠檬酸络合法制备的 Mn(x)Ce(1)-(x)O(2) (x: 0.3-0.9) 作为催化剂用于甲醛 (HCHO) 的热催化氧化。在 x=0.3 和 0.5 时，大部分锰掺入到 CeO(2) 的萤石结构中形成固溶体。在 x=0.5 时催化活性最佳，此时达到 100%去除率的温度最低（270°C）。通过在 Mn(0.5)Ce(0.5)O(2) 中负载 5wt.% CuO(x)，可将 HCHO 氧化的 100%去除温度降低约 40°C。在气体流速为 10,000 hr⁻¹、臭氧浓度为 506 ppm 时，在 25°C 下，Mn(0.5)Ce(0.5)O(2) 催化剂对气相中浓度为 61 ppm 的 HCHO 进行催化氧化，可将其完全氧化。此外，还考察了 O(3)与 HCHO 的摩尔比的影响。当 O(3)/HCHO 从 3 增加到 8 时，HCHO 的去除效率从 83.3%增加到 100%。当 O(3)/HCHO 为 8 时，HCHO 向 CO(2)的矿化效率为 86.1%。在 25°C 下，p 型氧化物半导体 (Mn(0.5)Ce(0.5)O(2)) 对臭氧的分解效率高达 99.2%，显著高于 n 型氧化物半导体（TiO(2)）的低臭氧分解效率（9.81%）。在 GHSV 为 10,000 hr⁻¹、[O(3)]/[HCHO]=3 和温度为 25°C 的条件下，在 80 小时的耐久性测试中，始终保持较高的 HCHO 去除效率（≥81.2%），表明该催化剂在去除 HCHO 方面具有长期稳定性。
