PEG-2000添加量对Pr_(x)Zr_(1-x)O_(2-δ)催化氧化NO活性的影响

Effect of polyethylene glycol-2000 addition on catalytic activity of Pr_(x)Zr_(1-x)O_(2-δ)for oxidation of NO

采用溶胶-凝胶法制备了Pr_(x)Zr_(1-x)O_(2-δ)催化剂,并用于NO催化氧化。以聚乙二醇-2000(PEG-2000)为模板剂对催化剂进行改性,研究了不同模板剂添加质量分数对NO催化氧化活性的影响。结果表明,催化剂活性随PEG-2000添加质量分数的增加而降低;在300℃、PEG-2000添加质量分数为2%时,Pr_(x)Zr_(1-x)O_(2-δ)的催化活性最高,NO转化率达到了94.81%。利用XRD、SEM、N2吸附-脱附、XPS及FT-IR对催化剂进行表征,结果表明,模板剂添加质量分数的变化不会改变催化剂Pr_(2)Zr_(2)O_(7)晶型;催化剂为介孔结构,质量分数为2%时的比表面积和孔容最大,有利于催化氧化NO。此外,模板剂质量分数的增加会增强催化剂的亲水性。

Pr_(x)Zr_(1-x)O_(2-δ)catalyst is prepared through a sol gel method and served for NO catalytic oxidation.The catalyst is modified with polyethylene glycol-2000(PEG-2000)as template agent,and the effect of different template dosages on the catalytic activity of the catalyst in NO oxidation is studied.Results show that the activity of catalyst decreases with the increase of PEG-2000 addition ratio.Pr_(x)Zr_(1-x)O_(2-δ)has the highest activity when the dosage of PEG-2000 is 2%at 300℃,over which the conversion rate of NO reaches 94.81%.XRD,SEM,N2 adsorption/desorption,XPS and FT-IR are employed to characterize the catalyst.It is shown that the change of template agent dosage does not change the crystal form of Pr_(2)Zr_(2)O_(7)catalyst.The catalyst has a mesoporous structure,and the largest specific surface area and pore volume when the dosage of template agent is 2%,which is conducive to catalytic oxidation of NO.In addition,the higher content of template agent can enhance the hydrophilicity of the catalyst.