*Article* **Promotion Effect of the Keggin Structure on the Sulfur and Water Resistance of Pt/CeTi Catalysts for CO Oxidation**

**Tong Zhang <sup>1</sup> , Wenge Qiu 1,\* , Hongtai Zhu <sup>1</sup> , Xinlei Ding <sup>1</sup> , Rui Wu <sup>2</sup> and Hong He <sup>1</sup>**


**\*** Correspondence: qiuwenge@bjut.edu.cn

**Abstract:** Developing a catalyst with high SO<sup>2</sup> and H2O resistance to achieve high-performance CO oxidation for specific industrial applications is highly desirable. Here, three catalysts were prepared using cerium titanium composite oxide (CeTi), molybdophosphate with Keggin structure-modified CeTi (Keg-CeTi), and molybdophosphate without Keggin structure-modified CeTi (MoP-CeTi) as supports, and their sulfur and water resistance in CO oxidation were tested. The characterization of XRD, BET, SO2/H2O-DRIFTS, XPS, TEM, SEM, NH3/SO<sup>2</sup> -TPD, H<sup>2</sup> -TPR, and ICP techniques revealed that the high SO<sup>2</sup> and H2O resistance of Pt/Keg-CeTi in CO oxidation was related to its stronger surface acidity, better reduction of surface cerium and molybdenum species, and lower SO<sup>2</sup> adsorption and transformation compared to Pt/CeTi and Pt/MoP-CeTi.

**Keywords:** CO oxidation; sulfur and water resistance; platinum-based catalyst; Keggin structure
