Ag(x)/ZSM-5催化剂的CH4-SCR脱硝性能

Catalytic performance of Ag(x)/ZSM-5 catalysts for selective catalytic reduction of nitric oxide by methane

采用浸渍法制备Ag(x)/ZSM-5(x=3、6、9)催化剂。采用XRD、SEM、NH3-TPD、Py-FTIR、XPS和NO-TPD等手段对催化剂的理化性质进行表征,在常压固定床微型反应器中评价催化剂甲烷选择性催化还原(CH4-SCR) NO催化性能,考察Ag负载量对Ag(x)/ZSM-5催化剂CH4-SCR脱硝性能的影响。结果表明,ZSM-5分子筛负载Ag,催化剂的酸性和酸量发生变化,改善了催化剂对NO的吸附脱附性能。随着Ag负载量增加,形成较大的Ag晶粒,有利于甲烷活化,Ag(x)/ZSM-5催化剂CH4-SCR脱硝活性提高。Ag(9)/ZSM-5催化剂CH4-SCR脱硝性能较好,在350℃时NO转化率为41.87%。

Ag(x)/ZSM-5(x= 3,6,9) catalysts for selective catalytic reduction of nitric oxide by methane( CH4-SCR) were prepared by impregnation method. The physicochemical properties of the catalysts were characterized by XRD,SEM,NH3-TPD,Py-FTIR,XPS and NO-TPD. The catalytic performance for selective catalytic reduction of nitric oxide by methane was evaluated in a fixed-bed micro-reactor under atmospheric pressure and the influence of Ag loading were investigated. The results show that the impregnation of Ag has changed the acidity and amount of acid of the catalyst and improved the adsorption and desorption performance of NO on ZSM-5 molecular sieve. With the increase of Ag loading,Ag particle size increases and results in higher methane activation as well as the denitration activity of CH4-SCR over Ag( x)/ZSM-5 catalyst. Ag( 9)/ZSM-5 has better denitration activity and the NO conversion is 41.87% at 350 ℃.