One-pot synthesis of ceria and cerium phosphate (CeO-CePO) nanorod composites for selective catalytic reduction of NO with NH: Active sites and reaction mechanism.

In this work, novel (CeO)-(CePO) (defined as CeP) nanorod composites were prepared by a simple co-precipitation method, and the influence of CeO on the catalytic performance of CePO for selective catalytic reduction of NO by NH (NH-SCR of NO) was investigated. The catalytic performance evaluation revealed that the CeP catalysts, especially CeP exhibited a much better catalytic activity and HO + SO resistance than CePO. Structure characterizations via high-resolution transmission electron microscope (HRTEM) and Brunauer-Emmett-Teller (BET) revealed that the introduction of CeO had a little effect on the shape of CePO nanorods and it could promote the formation of new mesoporous then significantly enhance the surface area of catalyst. The analysis results of active sites suggested that phosphorus was the main adsorption site for NH and the redox sites were controlled by CeO on CeP catalysts. Finally, reaction process study demonstrated that the NH-SCR over CeP was processed via Langmuir-Hinshelwood (L-H) mechanism. Combining the results of active sites and reaction mechanism analysis, it was drawn that the superior low temperature activity of CeP could be attributed to its excellent redox properties, which promoted the oxidation of NO then facilitated the process of NH-SCR via "fast SCR".