We have studied the adsorption of NO, and the coadsorption of N and O, on four physical and hypothetical systems: unstrained and strained Rh(100) surfaces and monolayers of Rh atoms on strained and unstrained MgO(100) surfaces. We find that as we go from Rh(100) to Rh/Mg0(100), via the other two hypothetical systems, the effective coordination progressively decreases, the $d$-band narrows and its center shifts closer to the Fermi level, and the strength of adsorption and co-adsorption increases. Both strain and the presence of the oxide substrate contribute significantly to this. However, charge-transfer is found to play a negligible role, due to a cancelling out between donation and back-donation processes. Our results suggest that lowering effective coordination of Rh catalysts by strain, roughening or the use of inert substrates might improve reaction rates for the reduction of NO to N$_2$.
Ab initio statistical mechanics of surface adsorption and desorption: I. H$_2$O on MgO (001) at low coverage
我们提出了一个通用的计算方案的基础上分子动力学（m.d.）模拟计算吸附分子在材料表面处于热平衡时的化学势。该方案基于平均力的计算（单位：m. d）。模拟，其中所选分子在表面上方的高度受到限制，随后对平均力进行积分，以获得平均力的势，从而获得化学势。该方案在任何覆盖率和温度下都是有效的，因此原则上它允许计算作为覆盖率和温度的函数的化学势。它避免了所有的统计力学近似，除了使用经典的统计力学的核，并假定没有预先的吸附网站。从化学势，可以计算分子的绝对解吸速率，只要表面上的平衡速率比解吸速率快。我们应用{ \em ab initio} m.d.用Perdew-Burke-Ernzerhof（PBE）交换相关模型模拟了MgO（001）上H $_2$ O在低覆盖度下的情况。计算得到Polanyi-Wigner频率前因子的{ \em ab initio}值，该值比过去通常假设的$10^{13}$ s $^{-1}$的值大两个数量级以上。与实验的临时比较表明，PBE吸附能可能太低，但在得出确切的结论之前，需要将计算扩展到更高的覆盖率。包括量子核效应的可能性，使用路径积分模拟指出。
Lowering the Exponential Wall: Accelerating High-Entropy Alloy Catalysts Screening using Local Surface Energy Descriptors from Neural Network Potentials
