Yan Pu, Zhang Dong, Zhang Wendi, Sun Kaijun, Jin Meng, Chamberlain Thomas W, Khlobystov Andrei N, Kaiser Ute, Hu Yuan, Cao Kecheng
School of Physical Science and Technology & Shanghai Key Laboratory of High-Resolution Electron Microscopy, ShanghaiTech University, Shanghai 201210, China.
School of Chemistry, University of Leeds, Leeds, West Yorkshire LS2 9JT, U.K.
ACS Nano. 2025 Jul 1;19(25):23306-23314. doi: 10.1021/acsnano.5c06292. Epub 2025 Jun 13.
Transition of metal-to-metal carbide plays a key role in heterogeneous catalysis. We confined nickel nanocrystals in single-walled carbon nanotubes, stimulated delivery of carbon atoms by the 80 keV electron beam, and imaged the entire carbonization process by time-resolved aberration-corrected transmission electron microscopy at the atomic scale. Metal nanocrystal Ni progressively capturing carbon atoms evolved from pure metal to NiC and then to NiC. The carbonization is accompanied by changes in the structure of the crystal, including a two-dimensionalization process, at the NiC stage. This work provides valuable insights into the atomic mechanism of metal carbide formation, which may help to develop stable catalysts and provide a reliable route for synthesizing metal-based two-dimensional materials.
金属到金属碳化物的转变在多相催化中起着关键作用。我们将镍纳米晶体限制在单壁碳纳米管中，用80 keV电子束刺激碳原子的传递，并通过时间分辨的像差校正透射电子显微镜在原子尺度上对整个碳化过程进行成像。金属纳米晶体镍逐渐捕获碳原子，从纯金属演变为NiC，然后再变为NiC₂。碳化过程伴随着晶体结构的变化，包括在NiC阶段的二维化过程。这项工作为金属碳化物形成的原子机制提供了有价值的见解，这可能有助于开发稳定的催化剂，并为合成金属基二维材料提供可靠的途径。
