The chemical state of metallic site is crucial for the performance of supported catalysts. Due to the difference of metal-support interaction, the chemical states of the supported metallic species are usually various and identifying the most active site is therefore very important for the design of efficient catalysts. In this work, a superior Pt species with high positive charge is identified as the active site in the hydrogen-borrowing amination of cyclopentanol with cyclopentylamine structure and performance relationship study over Pt/CeO catalyst. It is found that the lower Pt loaded catalyst (0.74 %Pt/CeO) has much higher activity than that of the higher Pt loaded one (1.5 %Pt/CeO). CO-DRIFTs and XANES studies show that Pt in 0.74 %Pt/CeO catalyst has higher positive charge, favoring the dehydrogenation of cyclopentanol to cyclopentanone, the rate-determining step in the whole reaction. Furthermore, a 0.38 %Pt/CeO catalyst was prepared, which shows excellent performance at lower temperature (80 °C), the mildest reaction conditions investigated up to now. This work provides a new sight in the design of excellent catalysts for the hydrogen-borrowing amination under mild reaction conditions.

中文翻译：

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鉴定用于醇低温借氢胺化的优质 Ptδ+ 物种

金属位点的化学状态对于负载型催化剂的性能至关重要。由于金属-载体相互作用的差异，负载金属物种的化学态通常是多种多样的，因此识别最活跃的位点对于高效催化剂的设计非常重要。在这项工作中，我们确定了一种具有高正电荷的优质 Pt 物种作为环戊醇借氢胺化反应中的活性位点，并研究了 Pt/CeO 催化剂上环戊胺的结构和性能关系。结果发现，较低 Pt 负载量的催化剂 (0.74%Pt/CeO) 比较高 Pt 负载量的催化剂 (1.5%Pt/CeO) 具有更高的活性。 CO-DRIFT 和 XANES 研究表明，0.74%Pt/CeO 催化剂中的 Pt 具有较高的正电荷，有利于环戊醇脱氢生成环戊酮，这是整个反应的速率决定步骤。此外，还制备了0.38%Pt/CeO催化剂，该催化剂在较低温度（80℃）下表现出优异的性能，这是迄今为止研究的最温和的反应条件。该工作为温和反应条件下的借氢胺化优异催化剂的设计提供了新的思路。