NaOH-Modified Ceramic Honeycomb with Enhanced Formaldehyde Adsorption and Removal Performance
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- 作者：Jiaguo Yu ; Xinyang Li ; Zhihua Xu ; Wei Xiao
- 刊名：Environmental Science & Technology
- 出版年：2013
- 出版时间：September 3, 2013
- 年：2013
- 卷：47
- 期：17
- 页码：9928-9933
- 全文大小：385K
- 年卷期：v.47,no.17(September 3, 2013)
- ISSN：1520-5851
文摘
NaOH-modified ceramic honeycombs (Na鈥揅H) were simply prepared by impregnating ceramic honeycombs (CH) into NaOH aqueous solution. It was clearly shown that the surface modification incurs higher specific surface area and smaller grain sizes of the CH without destruction of their integrity. Moreover, the introduced surface NaOH can trigger Cannizzaro disproportionation of surface-absorbed formaldehyde (HCHO) on Na鈥揅H, resulting in catalytic transformation of HCHO into less-toxic formate and methoxy salts. The NaOH concentration during impregnating treatment has a great influence on HCHO adsorption and removal efficiency, while the impregnation time and temperature have little influence on the efficiency. When the CH was impregnated in 1 M NaOH aqueous solution for 0.5 h at room temperature, the HCHO removal efficiency at ambient temperature can reach about 80% with an initial HCHO concentration of 250 ppm. Moreover, the used Na鈥揅H can be facilely regenerated via 1 min blow using a common electric hair dryer, with the generation of less toxic HCOOH and CH3OH and recovery of NaOH. Using such a mild, fast, and practical regeneration method, the regenerated Na鈥揅H showed slight degradation in adsorption and removal capability toward HCHO. The enhanced performance of Na鈥揅H obtained was attributed to the presence of NaOH and increase of specific surface area and surface hydroxyl groups. Considering no demand of noble metal for HCHO removal at ambient temperature and practical reusable capability of Na鈥揅H under mild conditions, this work may provide some new insights into the design and fabrication of advanced catalysts for indoor air purification.