Mg/Al物质的量比对Ce-La/MgAl2O4-x催化剂催化CO还原NO性能的影响

采用初始浸渍法制备了不同Mg/Al物质的量比的Ce-La/MgAl₂O₄-x催化剂，并通过低温N₂-吸附脱附、XRD、H₂-TPR和CO-TPR等手段对其进行了表征。结果表明，在Mg/Al物质的量比为0.5时，催化剂催化CO还原NO的性能最好。这主要是因为适量Mg的添加促进了CeO₂的分散和Ce-O-La固溶体的形成，从而使得表面Ce³⁺和氧空穴增加。两者的协同作用使得Ce-La/MgAl₂O₄-0.5表现出最佳的催化性能。另外，适量Mg的引入可以抑制Ce（SO₄）₂和Ce₂（SO₄）₃的形成，从而提高了Ce-La/MgAl₂O₄-0.5催化剂抗硫中毒能力。

Effect of Mg/Al molar ratios on NO reduction activity of CO using Ce-La/MgAl2O4-x catalysts

A series of Ce-La/MgAl₂O₄-x catalysts were prepared by the incipient wetness impregnation method and characterized by BET, XRD, H₂-TPR, CO-TPR and in situ FT-IR. The results demonstrate that the catalyst with a Mg/Al molar ratio of 0.5 yields the most uniform dispersion of CeO₂ and greatly enhances formation of Ce-O-La solid solution, resulting in the increase of oxygen vacancy and surface Ce³⁺ content. Thereby,the synergistic effect between surface Ce³⁺ and oxygen vacancy gives rise to the best catalytic performance of NO reduction. Moreover, introduction of Mg species suppresses tranformation of CeO₂ to Ce(SO₄)₂/Ce₂(SO₄)₃ and then improves the SO₂ resistance performance of Ce-La/MgAl₂O₄-0.5.