Cerium(III) Nitrate Derived CeO2 Support Stabilising PtOx Active Species for Room Temperature CO Oxidation

A new approach for preparing a PtOx/CeO2 catalyst for low‐temperature CO oxidation has been developed. The approach includes; i) preparation of a CeO2 support through the controllable thermal decomposition of Ce(NO3)3 ⋅ 6H2O, and then ii) deposition of polynuclear platinum nitrato complexes ([H3O⊂18‐crown‐6]2[Pt2(μ2‐OH)2(NO3)8][Pt4(μ3‐OH)2(μ2‐OH)4(NO3)10]) on the CeO2 support. The NO3−‐rich ceria support produced at the onset temperature of Ce(NO3)3 ‐> CeO2 transformation (220 °C) yields the “PtOx/CeO2‐220” 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). Low‐temperature CO oxidation: Polynuclear platinum(IV) nitratocomplexes deposited on a nitrate‐rich ceria support transform into highly active catalysts for CO oxidation with a striking performance at room temperature and below.