Shen Xiangjian, Li Yuanjie, Liu Xianglin, Zhang Dandan, Gao Jian, Liang Tianshui
Research Center of Heterogeneous Catalysis and Engineering Sciences, School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China and State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
Research Center of Heterogeneous Catalysis and Engineering Sciences, School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China.
Phys Chem Chem Phys. 2017 Feb 1;19(5):3557-3564. doi: 10.1039/c6cp07830c.
Diffusion pathways of atomic hydrogen on model catalyst surfaces and into subsurfaces are of great significance in the exploration of novel catalytic hydrogenation in heterogeneous catalysis. We present in detail the diffusion pathways of hydrogen on seven different open and closed model catalyst surfaces from first principles calculations. Seven transition metal catalysts with thirteen different crystal surfaces, i.e., Co(001), Ni(100) and Ni(111), Pd(100) and (111), Pt(100) and (111), Cu(100) and (111), Ag(100) and (111) and Au(100) and (111), are taken into account. Thirteen corresponding potential energy surfaces (PESs) are constructed for modelling hydrogen diffusion on these model catalyst surfaces and into the subsurfaces by interpolating ab initio density functional theory energy points (∼2000 for each surface). The minimum energy diffusion pathways for hydrogen on the surfaces and into the subsurfaces are globally searched for based on PESs using a mesh method, and are in excellent agreement with those calculated from the nudged elastic band method. Furthermore, the important substrate relaxation effect can decrease the diffusion barriers for hydrogen into catalyst subsurfaces. The high reactivity of subsurface reactants mainly comes from the residual energy of subsurface hydrogen emerging from the subsurface onto the surface.
在多相催化中探索新型催化加氢过程时，原子氢在模型催化剂表面及次表面的扩散路径具有重要意义。我们通过第一性原理计算详细展示了氢在七种不同的开放和封闭模型催化剂表面的扩散路径。考虑了七种具有十三种不同晶体表面的过渡金属催化剂，即Co(001)、Ni(100)和Ni(111)、Pd(100)和(111)、Pt(100)和(111)、Cu(100)和(111)、Ag(100)和(111)以及Au(100)和(111)。通过对从头算密度泛函理论能量点（每个表面约2000个）进行插值，构建了十三个相应的势能面（PESs），用于模拟氢在这些模型催化剂表面及次表面的扩散。基于PESs，使用网格方法全局搜索氢在表面及次表面的最小能量扩散路径，其与用推挤弹性带方法计算的结果高度吻合。此外，重要的底物弛豫效应可以降低氢进入催化剂次表面的扩散势垒。次表面反应物的高反应活性主要来自次表面氢从次表面逸出到表面时所剩余的能量。
