PDF(Pubmed)
Abstract：
Understanding the operando defect-tuning performance of catalysts is critical to establish an accurate structure-activity relationship of a catalyst. Here, with the tool of single-molecule super-resolution fluorescence microscopy, by imaging intermediate CO formation/oxidation during the methanol oxidation reaction process on individual defective Pt nanotubes, we reveal that the fresh Pt ends with more defects are more active and anti-CO poisoning than fresh center areas with less defects, while such difference could be reversed after catalysis-induced step-by-step creation of more defects on the Pt surface. Further experimental results reveal an operando volcano relationship between the catalytic performance (activity and anti-CO ability) and the fine-tuned defect density. Systematic DFT calculations indicate that such an operando volcano relationship could be attributed to the defect-dependent transition state free energy and the accelerated surface reconstructing of defects or Pt-atom moving driven by the adsorption of the CO intermediate. These insights deepen our understanding to the operando defect-driven catalysis at single-molecule and subparticle level, which is able to help the design of highly efficient defect-based catalysts.
摘要：
了解催化剂的操作缺陷调节性能对于建立催化剂的准确结构-活性关系至关重要。这里,使用单分子超分辨率荧光显微镜的工具，通过在单个有缺陷的Pt纳米管上对甲醇氧化反应过程中的中间CO形成/氧化进行成像，我们发现，具有较多缺陷的新鲜Pt末端比具有较少缺陷的新鲜中心区域更活跃和抗CO中毒，而这种差异可以在催化诱导的Pt表面上逐步产生更多缺陷后逆转。进一步的实验结果揭示了催化性能（活性和抗CO能力）与微调缺陷密度之间的操作性火山关系。系统的DFT计算表明，这种操作火山关系可归因于与缺陷相关的过渡态自由能以及由CO中间体吸附驱动的缺陷或Pt原子移动的加速表面重建。这些见解加深了我们对单分子和亚粒子水平的操作缺陷驱动催化的理解，这能够帮助设计高效的基于缺陷的催化剂。
