To stabilize Pt, Magnesium-modified SiO 2 -Al 2 O 3 materials was used to impregnate with Pt, which could strengthen the bonding effect between Pt and Mg. Before and after aging, both showed a higher dispersion. High valence state of Pt in fresh modified catalyst was unfavorable of NO oxidation, indicating that the valence state of Pt was the leader factor in fresh catalytic performance. While for the aged Mg-modified sample, its reaction temperature of 30% NO conversion lowered by around 30 °C. The Pt stabilization via interacting with Mg derives a relation that the variation of Pt valence state and its exposed sites played a significant role in fresh and aged catalytic NO activity, respectively.
Liang, Y., Ding, X., Zhao, M., Wang, J., & Chen, Y. (2018). Effect of valence state and particle size on NO oxidation in fresh and aged Pt-based diesel oxidation catalysts. Applied Surface Science, 443, 336–344. https://doi.org/10.1016/j.apsusc.2018.03.032