Feng Xilan, Li Wang, Liu Dapeng, Zhang Zheng, Duan Yang, Zhang Yu
Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, China.
International Research Institute for Multidisciplinary Science, Beihang University, Beijing, 100191, P. R. China.
Small. 2017 Aug;13(31). doi: 10.1002/smll.201700941. Epub 2017 Jun 14.
Pd@CeO /Al O catalysts are of great importance for real applications, such as three-way catalysis, CO oxidation, and methane combustion. In this article, the Pd@CeO core@shell nanospheres are prepared via the autoredox reaction in aqueous phase. Three kinds of methods are then employed, that is, electrostatic interaction, supramolecular self-assembly, and physical mixing, to support the as-prepared Pd@CeO nanospheres on γ-Al O . A model reaction of catalytic methane-combustion is employed here to evaluate the three Pd@CeO /γ-Al O samples. As a result, the sample Pd@CeO -S-850 prepared via supramolecular self-assembly and calcined at 850 °C exhibits superior catalytic performance to the others, which has a far lower light-off temperature (T of about 364 °C). Moreover, almost no deterioration of Pd@CeO -S-850 is observed after five sequent catalytic cycles. The analysis of H -TPR curves concludes that there exists hydrogen spillover related to the strong metal-support interaction between Pd species and oxides. The strong metal-support interaction and the specific surface areas might be responsible for the catalytic performance of the Pd@CeO samples toward catalytic methane combustion.
钯@二氧化铈/氧化铝催化剂对于实际应用非常重要，例如三元催化、一氧化碳氧化和甲烷燃烧。在本文中，通过水相中的自氧化还原反应制备了钯@二氧化铈核壳纳米球。然后采用三种方法，即静电相互作用、超分子自组装和物理混合，将制备好的钯@二氧化铈纳米球负载在γ-氧化铝上。这里采用催化甲烷燃烧的模型反应来评估这三种钯@二氧化铈/γ-氧化铝样品。结果表明，通过超分子自组装制备并在850℃煅烧的样品钯@二氧化铈-S-850表现出优于其他样品的催化性能，其起燃温度（T约为364℃）低得多。此外，在五个连续的催化循环后，几乎未观察到钯@二氧化铈-S-850的性能恶化。对氢气程序升温还原（H-TPR）曲线的分析得出结论，存在与钯物种和氧化物之间的强金属-载体相互作用相关的氢溢流。强金属-载体相互作用和比表面积可能是钯@二氧化铈样品对催化甲烷燃烧催化性能的原因。
