CuO/Mn2O3/γ-Al2O3催化剂的制备、表征及其在CO氧化反应中的性能研究

摘要

A series CuO/Mn2O3/r-Al2O3 catalysts were prepared by impregnation and characterized by XR.F, XRD, H2-TPR, in-situ FT-IR and activity test for oxidation of carbon monoxide. The model reaction of CO+O2 tests showed that, modification of r-Al2O3 by Mn2O3 promoted activities of CuO/r-Al2O3 catalysts. XRD results proved that the amount of well-dispersed Cu2+ species was increased after the modification by Mn2O3, and it was also found that the catalytic activities were not only decided by the amount of well-dispersed Cu2+ species. Furthermore, TPR and in-situ FT-IR results revealed that the activities of catalysts were in good line with the reducibility of well-dispersed copper and manganese oxides species.%采用浸渍法在γ-Al2O3载体上分步负载改性剂Mn2O3和活性组分CuO,制备了一系列不同配比的CuO/Mn2O3/γ-Al2O3催化剂,并运用CO+O2模型反应、XRF、XRD、H2-TPR、in-situ FTIR等手段表征了催化剂的活性和物理化学性质.活性测试结果表明,锰氧化物对γ-Al2O3载体的改性能有效地提高CuO/γ-Al2O3催化剂在CO+O2模型反应中的催化活性.XRD结果表明,锰氧化物对γ-Al2O3载体的改性可以促进氧化铜在载体表面的分散,从而提高了分散态氧化铜的含量,不过这与活性变化的趋势并不完全一致.进一步结合H2-TPR、in-situ FTIR表征结果,我们发现,分散态铜、锰氧化物的还原性质也是影响其催化活性的重要因素,催化剂中分散态铜、锰物种越容易被还原,其对CO+O2模型反应的催化活性就越高.