Size-dependent CO and propylene oxidation activities of platinum nanoparticles on the monolithic Pt/TiO2-YOx diesel oxidation catalyst under simulative diesel exhaust conditions

作者：Yang, Zhengzheng; Li, Jun; Zhang, Hailong; Yang, Yi; Gong, Maochu; Chen, Yaoqiang^*

来源：Catalysis Science & Technology, 2015, 5(4): 2358-2365.

DOI：10.1039/c4cy01384k

• NO OXIDATION
• PT/AL2O3 CATALYSTS
• CARBON-MONOXIDE
• OXIDE FORMATION
• PARTICLE-SIZE
• DEACTIVATION
• DISPERSION
• REDUCTION
• CRYSTALS
• CLUSTERS

In this work, we determined the CO and C3H6 oxidation rates of size-selected Pt nanoparticles (1 nm ultrafine size and 8.8 nm nanoscale size average diameters) deposited on TiO2-YOx supports. Both Pt/TiO2-YOx catalysts were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and H-2 temperature-programmed reduction (H-2-TPR). The results show that platinum particles on the fresh as-synthesized catalysts are fully oxidized to PtO2 during calcination in air; PtO2 can be partly regenerated to the Pt-0 active phase under oxygen rich diesel exhaust conditions (containing about 1000 ppm CO), in which the ultrafine Pt particles supplying a larger surface to volume ratio are more beneficial for Pt-0 regeneration than the nanoscale ones. Such regeneration of Pt-0 occurred even under oxygen rich diesel exhaust conditions, leading to a significantly better global catalytic performance for the DOC reaction. Thus, this work suggests that Pt-0 occupation ratio under DOC reaction conditions may become a criteria for identifying the quality of DOC catalysts.

• 出版日期2015
• 单位四川大学