Low temperature reaction mechanism of NH3-SCR reaction on MoOx modified CePO4 catalyst: Combination study on experiments and DFT calculations.

• The study combines computational and experimental work on the Mo x Ce 1- x PO 4. • The incorporation of Mo improved the NH 3 -SCR activity on the Mo x Ce 1- x PO 4. • The reaction mechanism followed the Eley-Rideal and Langmuir-Hinshelwood mechanism. Developing CePO 4 -based NH 3 -SCR catalysts with high NO x conversion, N 2 selectivity, and SO 2 tolerance at low temperatures is challenging. Analyzing the atomic-level surface structure of these catalysts is particularly important. Hence, we conducted a combined computational and experimental study to design the surface structure of Mo x Ce 1- x PO 4 catalysts, corroborate the reaction performance and structural sensitivity, and investigate the relationship between active sites and structural performance at the atomic level. DFT calculations were used to systematically investigate the NH 3 and NO adsorption capacity of the Mo-doped CePO 4 solid solution structure model. The rationality of using the Mo-doped CePO 4 solid solution structure as a catalyst was further supported by DFT calculation data and experimental results from BET, XRD, Raman, SEM, TEM, HR-TEM, NH 3 -TPD, H 2 -TPR, XPS and in situ DRIFTS. The source of the excellent intrinsic NH 3 -SCR activity of the Mo-doped CePO 4 solid solution structure is disclosed. The role of the Mo dopant in the Mo-doped CePO 4 solid solution as an SO 2 trapping site to protect the catalytic active site from sulfation is discussed from a molecular perspective. [ABSTRACT FROM AUTHOR]