【摘要】 考察了残余Cl-及水的添加对负载型Pd/Al2O3催化剂甲烷燃烧性能的影响.结果表明,含Cl-的催化剂活性较低,水的加入可使催化剂迅速失活,在高温下通过N2吹扫可使催化剂再生.采用N2吸附、X射线荧光分析、红外光谱和热重分析对催化剂进行了表征.结果表明,Cl-的存在会降低Pd在载体上的分散度,且对Pd/Al2O3催化剂的活性有强烈的抑制作用;添加的水会覆盖催化剂活性位并与PdO生成催化活性较低的Pd(OH)2,从而使得催化剂活性下降。更多还原

【Abstract】 The influences of residual chlorine ions and water on the performance of a Pd/Al2O3 catalyst in methane combustion have been studied.The results show that the catalyst containing Cl-exhibits a relatively low activity,and the addition of water to the reaction system accelerates the deactivation process.The catalyst has been characterized by N2 adsorption,X-ray fluorescence,Fourier transform infrared spectroscopy(FT-IR),and thermogravimetry(TG).The results show that the presence of Cl-appears to strongly inhibit the total oxidation of methane and hinder the dispersion of Pd on Al2O3.The formation of Pd(OH)2 during the reaction is the most likely reason for the inhibition effect of water,which is confirmed by FT-IR and TG analysis.The regeneration of the Pd/Al2O3 catalyst can be achieved by purging in nitrogen at 550 ℃.更多还原