摘要
采用程序升温表面反应 (TPSR) ,NH3 TPD ,TG MS和脉冲催化反应等手段研究了吡咯烷亚硝胺 (NPYR)在Fe2 O3 改性NaY沸石上的催化降解 .结果表明 ,用微波辐射、浸渍或焙烧等不同方法制备的改性沸石对NPYR降解的催化性能各不相同 ,以浸渍法制备的样品活性最高 ,但该样品对降解产物NO2 的吸附作用较弱 .在NPYR的降解反应中 ,Fe2 O3 改性NaY沸石上的Fe向沸石外表面迁移和富集 ,覆盖了沸石表面的铝 ,使催化剂表现出Fe2 O3 的性质 .
Recently more attention has been paid to the degradation of N-nitrosopyrrolidine (NPYR) that exists in cigarette smoke and is a threat to human health. Zeolites were used to degrade NPYR, but their catalytic activity needs to be enhanced. In this paper, the preparation and evaluation of the Fe 2O 3-modified NaY zeolite catalyst for the degradation of nitrosamines with high activity were reported. The catalyst samples were prepared by impregnation, microwave radiation, and calcination methods, characterized by XRD, NH 3-TPD and TG-MS techniques, and used in the temperature-programmed surface reaction (TPSR) and pulse reaction. Fe 2O 3 was dispersed more completely on the catalyst prepared by impregnation than that by microwave irradiation or by direct calcination. As a result, Fe 2O 3/NaY obtained by impregnating NaY with Fe(NO 3) 3 solution showed the highest activity for the degradation of NPYR. NO x was detected at 443 K in the TPSR process, representing the decomposition of NPYR, and reached the maximum amount at 533 K and the adsorption of product NO 2 on the sample was found to be weakened at the same time. The experiment of TG-MS revealed that the temperature of NO desorption on the impregnated sample decreased in comparison to the NaY zeolite. In the pulse reaction the Fe 2O 3/NaY catalyst showed high activity at 553 and 673 K, which may be related with the oxidation capability of Fe 2O 3 at high temperature. XPS results indicated that the Fe component in the catalyst can migrate from the inner surface to the external surface of NaY during the degradation of NPYR, covering the Al component on the catalyst surface and making the catalyst to exhibit characteristics of Fe 2O 3 in the reaction.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第7期499-504,共6页
基金
国家自然科学基金 (2 0 2 730 31)
南京大学分析中心资助项目
关键词
氧化铁
改性
NAY沸石
吡咯烷亚硝胺
催化降解
程序升温表面反应
iron oxide, modification, NaY zeolite, N-nitrosopyrrolidine, catalytic degradation, temperature-programmed surface reaction
