Jiang Dong, Yao Yonggang, Li Tangyuan, Wan Gang, Pereira-Hernández Xavier Isidro, Lu Yubing, Tian Jinshu, Khivantsev Konstantin, Engelhard Mark H, Sun Chengjun, García-Vargas Carlos E, Hoffman Adam S, Bare Simon R, Datye Abhaya K, Hu Liangbing, Wang Yong
The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, 99164, USA.
Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA.
Angew Chem Int Ed Engl. 2021 Dec 6;60(50):26054-26062. doi: 10.1002/anie.202108585. Epub 2021 Sep 9.
A single-atom Pt /CeO catalyst formed by atom trapping (AT, 800 °C in air) shows excellent thermal stability but is inactive for CO oxidation at low temperatures owing to over-stabilization of Pt in a highly symmetric square-planar Pt O coordination environment. Reductive activation to form Pt nanoparticles (NPs) results in enhanced activity; however, the NPs are easily oxidized, leading to drastic activity loss. Herein we show that tailoring the local environment of isolated Pt by thermal-shock (TS) synthesis leads to a highly active and thermally stable Pt /CeO catalyst. Ultrafast shockwaves (>1200 °C) in an inert atmosphere induced surface reconstruction of CeO to generate Pt single atoms in an asymmetric Pt O configuration. Owing to this unique coordination, Pt in a partially reduced state dynamically evolves during CO oxidation, resulting in exceptional low-temperature performance. CO oxidation reactivity on the Pt /CeO _TS catalyst was retained under oxidizing conditions.
通过原子捕获（AT，在空气中800°C）形成的单原子Pt/CeO催化剂表现出优异的热稳定性，但由于Pt在高度对称的四方平面PtO配位环境中过度稳定，在低温下对CO氧化无活性。还原活化形成Pt纳米颗粒（NPs）会提高活性；然而，这些NPs很容易被氧化，导致活性急剧损失。在此我们表明，通过热冲击（TS）合成来调整孤立Pt的局部环境会产生一种高活性且热稳定的Pt/CeO催化剂。在惰性气氛中产生的超快冲击波（>1200°C）诱导CeO的表面重构，以生成处于不对称PtO构型的Pt单原子。由于这种独特的配位，处于部分还原状态的Pt在CO氧化过程中动态演化，从而产生优异的低温性能。Pt/CeO_TS催化剂上的CO氧化反应活性在氧化条件下得以保留。
