The understanding of reaction mechanism is the theoretical premise for all the industrial improvement of catalysts. However, off-line characterization may mislead the study of catalytic mechanism if the catalyst itself is unstable during reaction. In this work, in-situ transmission electron microscopy (TEM) was emploied to investigate the photocatalysis process of H₂ evolution on Cu₂O. Real time imaging identified the self-reduction of Cu₂O to nano-Cu on particle surface and its catalytic activity was come from the self reduced nano-Cu. Further quantification results indicated that the degree of Cu₂O self-reduction was highly matched with the Cu₂O catalytic activity. The in-situ TEM here for the first time confirmed the in-situ formation of active site under reaction condition, these finding may beneficial for future catalyst design.

对反应机理的理解是所有催化剂工业改进的理论前提。但是，如果催化剂本身在反应过程中不稳定，则离线表征可能会误导催化机理的研究。在这项工作中，采用原位透射电子显微镜（TEM）来研究H ₂在Cu ₂ O上的光催化过程。实时成像鉴定了Cu ₂ O在颗粒表面上自还原为纳米Cu的过程，并对其进行了表征。催化活性来自于自还原纳米铜。进一步量化结果表明Cu的程度₂ O自拍还原高度与匹配的Cu ₂催化活性。这里的原位TEM首次证实了在反应条件下活性位的原位形成，这些发现可能对将来的催化剂设计有利。