Tian Hai-Kuo, Ban Tao, Su Xue, Luo De-Cun, Xiong Lei, Zhang Ming, Wang Fen-Zhong, Huang Zheng-Qing, Chang Chun-Ran
State Key Laboratory of Fluorine & Nitrogen Chemicals, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
Shaanxi Beiyuan Chemical Industry Group Co., Ltd., Jinjie Industrial Park, Shenmu City, Yulin 719319, China.
J Phys Chem Lett. 2025 Sep 11;16(36):9444-9452. doi: 10.1021/acs.jpclett.5c02077. Epub 2025 Sep 2.
ZnZrO catalysts exhibit excellent performance in the hydrogenation of CO to methanol, yet the structural identification of active sites in the mixed oxide remains elusive. Herein, combining density functional theory calculations, large-scale machine-learning atomic simulations, and microkinetic modeling, we discovered that double-chain ZnO structures supported on monoclinic ZrO(1̅11) surfaces (ZnO-ZrO) are highly active and stable for methanol synthesis. The double-chain ZnO structure, corresponding to 50% ZnO surface coverage and featuring interconnected 8-membered rings, induces a local minimum (0.28 eV per ZnO) in the average ZnO binding energy on ZrO(1̅11), indicating the stability of this structure. Unlike the single-atom Zn-doped ZrO(1̅11) structure (Zn-ZrO), possessing only isolated Zn-O-Zr sites, the ZnO-ZrO structure possesses both Zn-O-Zr (for CO adsorption) and Zn-O-Zn (for H dissociation) sites, enabling synergistic catalysis. Microkinetic simulations reveal an ∼4-fold higher methanol formation rate on ZnO-ZrO (2.35 s) than on Zn-ZrO (0.50 s) at 593 K. Overall, the identified ZnO-ZrO interface, with its dual functionality for CO and H activation and high methanol productivity, delivers crucial mechanistic insights into the active site over ZnZrO catalysts.
ZnZrO催化剂在将CO加氢制甲醇反应中表现出优异的性能，然而，这种混合氧化物中活性位点的结构识别仍然难以捉摸。在此，结合密度泛函理论计算、大规模机器学习原子模拟和微观动力学建模，我们发现，负载在单斜ZrO(1̅11)表面上的双链ZnO结构（ZnO-ZrO）对于甲醇合成具有高活性和稳定性。双链ZnO结构对应于50%的ZnO表面覆盖率，并具有相互连接的八元环，在ZrO(1̅11)上的平均ZnO结合能中诱导出一个局部最小值（每个ZnO为0.28 eV），表明该结构的稳定性。与仅具有孤立的Zn-O-Zr位点的单原子Zn掺杂ZrO(1̅11)结构（Zn-ZrO）不同，ZnO-ZrO结构同时具有Zn-O-Zr（用于CO吸附）和Zn-O-Zn（用于H解离）位点，能够实现协同催化。微观动力学模拟表明，在593 K时，ZnO-ZrO上的甲醇生成速率（2.35 s）比Zn-ZrO上的甲醇生成速率（0.50 s）高约4倍。总体而言，所确定的ZnO-ZrO界面具有CO和H活化的双重功能以及高甲醇生产率，为ZnZrO催化剂的活性位点提供了关键的机理见解。
