Fan Qi-Yuan, Liu Jing-Li, Gong Fu-Qiang, Wang Ye, Cheng Jun
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Phys Chem Chem Phys. 2022 May 11;24(18):10820-10825. doi: 10.1039/d2cp00678b.
The dynamic evolution of catalyst structures greatly influences the reactivity, especially sub-nanometer clusters, exhibiting complex configurational fluctuation. In the present work, we study the structural dynamics of a Ru cluster during the dissociation of N and calculate the reaction free energies using molecular dynamics (AIMD). Our AIMD calculation predicts a peak-shaped reaction entropy curve due to the adsorption-induced phase transition of the Ru cluster. The low melting points of sub-nanometer clusters make it possible to activate N at low temperatures. This work demonstrates that the dynamic changes of cluster structures have a non-negligible effect on reaction free energy and offer an opportunity for achieving ammonia synthesis under mild conditions.
催化剂结构的动态演变极大地影响反应活性，尤其是亚纳米团簇，其表现出复杂的构型波动。在本工作中，我们研究了Ru团簇在N解离过程中的结构动力学，并使用分子动力学（AIMD）计算反应自由能。我们的AIMD计算预测，由于Ru团簇的吸附诱导相变，反应熵曲线呈峰状。亚纳米团簇的低熔点使得在低温下活化N成为可能。这项工作表明，团簇结构的动态变化对反应自由能有不可忽视的影响，并为在温和条件下实现氨合成提供了机会。
