To develop highly active soot combustion catalysts for gasoline direct injection exhausts under low oxygen concentration conditions, CeO₂ supported-metal catalysts (M/CeO₂, M = Mn, Fe, Co, Ni, Cu, Rh, Pd, and Ag) were examined. Among the catalysts tested, Cu/CeO₂ and Rh/CeO₂ displayed the highest soot combustion activity. By comparing the activities of Cu-based catalysts with and without a Cu–CeO₂ interface, the importance of such an interface for soot combustion was inferred. The oxygen release rate of CeO₂-based catalysts, enhanced by metal–CeO₂ interactions, was indicated as the controlling factor of catalytic activity. The soot oxidation activity and oxygen release rate were also demonstrated to correlate with metal–oxygen bond energy. Based on the redox properties and structural characteristics of CeO₂-based catalysts, loading CeO₂ with Cu or Rh, which have moderate M–O bond energy, was concluded to be optimal both in terms of the dispersion of supported-metal species and reducibility of the CeO₂-based catalyst.

中文翻译：

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通过金属-载体相互作用调节CeO2基催化剂的氧气释放性能，以改善汽油烟灰燃烧

为了开发在低氧浓度条件下用于汽油直喷排气的高活性烟灰燃烧催化剂，使用了CeO ₂负载金属催化剂（M / CeO ₂，M = Mn，Fe，Co，Ni，Cu，Rh，Pd和Ag）检查。在测试的催化剂中，Cu / CeO ₂和Rh / CeO ₂显示出最高的烟combustion燃烧活性。通过比较具有和不具有Cu–CeO ₂界面的Cu基催化剂的活性，可以推断出这种界面对烟尘燃烧的重要性。金属–CeO _2可提高CeO ₂基催化剂的氧气释放速率相互作用被指示为催化活性的控制因素。烟灰的氧化活性和氧释放速率也被证明与金属-氧键能相关。根据CeO ₂基催化剂的氧化还原性质和结构特性，得出结论，在负载金属物种的分散性和还原性方面，将具有中等M–O键能的Cu或Rh负载在CeO ₂上是最佳的CeO ₂基催化剂的制备。