Active oxygen-promoted NO catalytic on monolithic Pt-based diesel oxidation catalyst modified with Ce

作者：Liang, Yanli; Ding, Xinmei; Dai, Jingyu; Zhao, Ming; Zhong, Lin; Wang, Jianli^*; Chen, Yaoqiang^*

来源：Catalysis Today, 2019, 327: 64-72.

DOI：10.1016/j.cattod.2018.06.008

• NO oxidation
• Ceria
• Dispersion
• active oxygen

Catalytic NO oxidation is crucial in oxidizing soot and promoting NH3 reduction during the emission eliminations of diesel vehicles by the modern after-treatment systems. To create more active oxygen species in favor of NO oxidation, ceria-modified monolithic Pt-based diesel oxidation catalyst was prepared by the step-impregnation method to improve its NO catalytic performance. Its NO maximum conversion was up to around 60% in the gas hourly space velocity of 60 kh(-1). Experimental results suggested that the ceria addition could have a better dispersion due to the inhibition effect of platinum aggregation. Especially, it is found that more active oxygen and oxygen vacancies over the catalyst played a significant role in strengthening the interaction of NO molecule with catalyst surface, resulting in the formation and transformation of more bridging/chelating nitrates confirmed by in situ FTIR studies. After thermal ageing, the catalyst with ceria addition still enabled a excellent NO catalytic performance, up to 50% NO maximum conversion. It would be proposed that active oxygen from the interaction bewteen ceria and Pt improved its NO catalytic activity and thermal-stability.

• 出版日期2019-5-1
• 单位四川大学