Liu Yijing, Lin Le, Mu Rentao, Fu Qiang
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Phys Chem Lett. 2024 Sep 19;15(37):9369-9373. doi: 10.1021/acs.jpclett.4c02133. Epub 2024 Sep 6.
Oxygen vacancies on the oxide surface are regarded to play critical roles in catalytic oxidation reactions because they can alter the electronic and geometric properties of oxide catalysts. However, the effects of the oxygen vacancy on the CO oxidation activity of the surrounding lattice oxygen have remained elusive. In this work, using high-pressure scanning tunneling microscopy we identify that oxygen vacancy can activate surface lattice oxygen on the MnO thin layer. It is found that CO reacts with the lattice oxygen located at the second-nearest-neighbor position to the original oxygen vacancies more easily than that at the closest position and at the defect-free surface. This can be ascribed to the lower formation energy of the oxygen vacancies. Our study provides atomic-level insights into the promoting effect of oxygen vacancies on catalytic oxidation reactions.
氧化物表面的氧空位被认为在催化氧化反应中起着关键作用，因为它们可以改变氧化物催化剂的电子和几何性质。然而，氧空位对周围晶格氧的CO氧化活性的影响仍然不清楚。在这项工作中，我们使用高压扫描隧道显微镜确定氧空位可以激活MnO薄层上的表面晶格氧。研究发现，CO与位于离原始氧空位第二近邻位置的晶格氧反应比与最近邻位置和无缺陷表面的晶格氧反应更容易。这可以归因于氧空位较低的形成能。我们的研究为氧空位对催化氧化反应的促进作用提供了原子水平的见解。
