Cerium(III) Nitrate Derived CeO 2 Support Stabilising PtO x Active Species for Room Temperature CO Oxidation

A new approach for preparing a PtO x /CeO 2 catalyst for low‐temperature CO oxidation has been developed. The approach includes; i) preparation of a CeO 2 support through the controllable thermal decomposition of Ce(NO 3 ) 3 ⋅ 6H 2 O, and then ii) deposition of polynuclear platinum nitrato complexes ([H 3 O⊂18‐crown‐6] 2 [Pt 2 (μ 2 ‐OH) 2 (NO 3 ) 8 ][Pt 4 (μ 3 ‐OH) 2 (μ 2 ‐OH) 4 (NO 3 ) 10 ]) on the CeO 2 support. The NO 3 − ‐rich ceria support produced at the onset temperature of Ce(NO 3 ) 3 ‐> CeO 2 transformation (220 °C) yields the “PtO x /CeO 2 ‐220” catalyst that shows intriguingly high activity in CO oxidation, at room temperature and below. To understand the nature of the low‐temperature catalytic activity, prepared catalysts have been studied using X‐ray photoelectron spectroscopy (XPS), Raman and operando X‐ray absorption fine structure spectroscopy (XAFS) and transmission electron microscopy (TEM).