用于低温CO氧化的CeO上单分散Pt的孤立双金属PtCe位点的原位形成
In Situ Formation of Isolated Bimetallic PtCe Sites of Single-Dispersed Pt on CeO for Low-Temperature CO Oxidation.
作者信息
Li Jing, Tang Yu, Ma Yuanyuan, Zhang Zhiyun, Tao Franklin Feng, Qu Yongquan
机构信息
Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, College of Chemistry and Chemical Engineering , Liaocheng University , Liaocheng 252059 , China.
Center for Applied Chemical Research, Frontier Institute of Science and Technology and Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology , Xi'an Jiaotong University , Xi'an 710049 , China.
出版信息
ACS Appl Mater Interfaces. 2018 Nov 7;10(44):38134-38140. doi: 10.1021/acsami.8b15585. Epub 2018 Oct 24.
Identification of the chemical states of catalytic sites is critical for an atomic-level understanding of catalytic mechanisms. Herein, hydrogen thermal pretreatment of the Pt single atoms on porous nanorods of CeO (Pt/ PN-CeO) induced the formation of isolated bimetallic PtCe sites as a new type of active center for CO oxidation. The evolutions of Pt/ PN-CeO catalysts during the hydrogen pretreatment and CO oxidation were examined by various in situ techniques including infrared, ambient-pressure X-ray photoelectron and X-ray absorption spectroscopy. The experimental results demonstrate that these bimetallic sites can be partially preserved or reoxidized into Pt-O-Ce with a low coordination number with oxygen under realistic conditions, leading to the appropriate CO adsorption and activating the efficient activity of Pt/ PN-CeO for CO oxidation at low temperature.
确定催化位点的化学状态对于从原子水平理解催化机制至关重要。在此，对CeO多孔纳米棒上的Pt单原子（Pt/PN-CeO）进行氢热预处理，诱导形成了孤立的双金属PtCe位点，作为CO氧化的新型活性中心。通过包括红外、常压X射线光电子能谱和X射线吸收光谱等各种原位技术研究了Pt/PN-CeO催化剂在氢预处理和CO氧化过程中的演变。实验结果表明，在实际条件下，这些双金属位点可以部分保留或重新氧化为与氧配位较低的Pt-O-Ce，从而导致适当的CO吸附并激活Pt/PN-CeO在低温下对CO氧化的高效活性。
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