Title: | Removal of formaldehyde over Mn(x)Ce(1)-(x)O(2) catalysts: thermal catalytic oxidation versus ozone catalytic oxidation |
Author(s): | Li JW; Pan KL; Yu SJ; Yan SY; Chang MB; |
Address: | "Graduate Institute of Environmental Engineering, National Central University, Chungli 32001, Taiwan, Chinese Taipei. Industrial Technology Research Institute, Hsinchu 31040, Taiwan, Chinese Taipei. Graduate Institute of Environmental Engineering, National Central University, Chungli 32001, Taiwan, Chinese Taipei. Electronic address: mbchang@ncuen.ncu.edu.tw" |
DOI: | 10.1016/j.jes.2014.05.030 |
ISSN/ISBN: | 1001-0742 (Print) 1001-0742 (Linking) |
Abstract: | "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 degrees C). The temperature for 100% removal of HCHO oxidation is reduced by approximately 40 degrees 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 O(3)over Mn(0.5)Ce(0.5)O(2) catalyst with a GHSV (gas hourly space velocity) of 10,000 hr(-)(1) at 25 degrees 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 degrees 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 degrees 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" |
Keywords: | "Air Pollution, Indoor/*prevention & control Catalysis Cerium/*chemistry Citric Acid/chemistry Formaldehyde/*isolation & purification Hot Temperature Manganese Compounds/*chemistry Oxidation-Reduction Ozone/*chemistry Formaldehyde Indoor air pollutant Ozon;" |
Notes: | "MedlineLi, Jia Wei Pan, Kuan Lun Yu, Sheng Jen Yan, Shaw Yi Chang, Moo Been eng Comparative Study Evaluation Study Netherlands 2014/12/17 J Environ Sci (China). 2014 Dec 1; 26(12):2546-53. doi: 10.1016/j.jes.2014.05.030. Epub 2014 Oct 22" |