Abstract In this paper, a comparative investigation of the catalytic performances of Pd@TiO2 and Pd@CeO2, core-shells nanocatalysts supported over functionalized alumina, for application to methane oxidation is presented. The results indicated that the Pd@CeO2/SiO2.Al2O3 core-shell nanocatalyst exhibited higher activity and stability than the Pd@TiO2/SiO2.Al2O3 nanocatalyst. Complete combustion of methane over the Pd@CeO2/SiO2.Al2O3 nanocatalyst was achieved at about 400 °C. By contrast, the maximum combustion of methane over the Pd@TiO2/SiO2.Al2O3 nanocatalyst was only attained at ∼550 °C. The Pd@TiO2/SiO2.Al2O3 nanocatalyst experienced deactivation, and a transient dip in methane conversion in the temperature region between 580 °C and 750 °C was also observed. The exceptional activity of the Pd@CeO2/SiO2.Al2O3 nanocatalyst was attributed to the intimate interaction between palladium (Pd) and ceria (CeO2) and efficient oxygen back-spillover at Pd and CeO2 interface resulting from the core-shell structure.

中文翻译：

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钯基核壳甲烷氧化纳米催化剂的合成、表征及性能

摘要 本文比较研究了负载在功能化氧化铝上的核壳纳米催化剂 Pd@TiO2 和 Pd@CeO2 用于甲烷氧化的催化性能。结果表明，Pd@CeO2/SiO2.Al2O3核壳纳米催化剂比Pd@TiO2/SiO2.Al2O3纳米催化剂表现出更高的活性和稳定性。甲烷在 Pd@CeO2/SiO2.Al2O3 纳米催化剂上的完全燃烧是在 400°C 左右实现的。相比之下，Pd@TiO2/SiO2.Al2O3 纳米催化剂上甲烷的最大燃烧仅在~550°C 时达到。Pd@TiO2/SiO2.Al2O3 纳米催化剂经历了失活，并且还观察到在 580°C 和 750°C 之间的温度范围内甲烷转化率的瞬时下降。Pd@CeO2/SiO2 的特殊活性。