Pt/Ce_xZr_(1-x)O_2/γ-Al_2O_3整体式催化剂上的氢气燃烧性能研究

研究了添加CexZr1-xO2对Pt/γ-Al2O3/堇青石整体式催化剂氢气催化燃烧性能的影响。结果表明,CexZr1-xO2的添加明显提高了催化剂的活性,并且随着Ce/Zr比的增大,催化剂活性逐渐增强。XRD结果显示,随着Ce/Zr比的增大,CexZr1-xO2立方相固溶体的衍射峰越来越明显,这表明Ce/Zr比的增大有利于CexZr1-xO2立方相固溶体的形成。N2吸附-脱附测试结果表明,添加10%质量分数的CexZr1-xO2对γ-Al2O3的比表面积影响不大,而使其孔径和孔容明显减小。当氢气浓度较低时,空速和湿度对氢气的转化率影响较大;而当氢气浓度较高时,空速和湿度对氢气的转化率影响不大。

Combustion behavior of hydrogen over Pt/CexZr1-xO2/γ-Al2O3 monolithic catalyst

The effect of CexZr1-xO2 on the performance of Pt /γ-Al2O3/cordierite monolithic catalyst in the catalytic combustion of hydrogen was studied. The results showed that the catalytic activity was obviously improved by the introduction of CexZr1-xO2 . With the increase of Ce/Zr ratio, the catalytic activity enhanced accordingly. The X-ray diffraction (XRD) patterns showed that the diffraction peaks intensity of CexZr1-xO2 cubic solid solution increased gradually with the increase of Ce/Zr ratio, which indicated that the increase of Ce/Zr ratio was helpful to the formation of CexZr1-xO2 cubic solid solution. The N2-sorption results showed that the specific surface area of γ-Al2O3 had not remarkable change after adding the CexZr1-xO2 , but its pore volume and pore size were obviously decreased. Hydrogen conversion was obviously affected by the water vapor partial pressure and space velocity of reaction mixture gas in low hydrogen concentration, but nearly not in high hydrogen concentration.