Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, CAS Center for Excellence in Nanoscience, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
Phys Chem Chem Phys. 2019 Mar 13;21(11):5950-5955. doi: 10.1039/c9cp00621d.
It is highly attractive but challenging to develop earth-abundant electrocatalysts for nitrogen (N2) fixation. Here, by using density functional theory (DFT), we systematically investigate various single transition metal atom (Ti, V, Cr, Mn, Fe, Co, Ni, Ru, Rh and Pd) modified MoP surfaces as potential N2 reduction electrocatalysts for ammonia (NH3) synthesis. Through comparison of the stabilities of metal atom modified MoP, the adsorption energies and the bond lengths of N2 on different atom modified MoP, we select Mn and V as two candidates and study in detail the possible N2 reduction reaction (NRR) pathways for Mn-MoP and V-MoP. Our results revealed that Mn-MoP and V-MoP exhibit energy change values of 0.95 eV and 0.65 eV, respectively, with the first hydrogenation step being the potential-limiting step. Mn-MoP can efficiently suppress *H adsorption and reduce the competition of the hygrogen evolution reaction (HER) with the NRR; whereas, V-MoP cannot. Therefore, Mn-MoP is a better catalyst to realize the nitrogen reduction reaction. Overall, this work takes one step toward the NRR possibility of transition metal phosphides and provides some important insights and guidance to experiments.
开发用于固氮的丰富地球元素电催化剂极具吸引力，但极具挑战性。在这里，我们通过使用密度泛函理论（DFT），系统地研究了各种单过渡金属原子（Ti、V、Cr、Mn、Fe、Co、Ni、Ru、Rh 和 Pd）修饰的 MoP 表面作为潜在的用于氨（NH3）合成的氮气还原电催化剂。通过比较金属原子修饰的 MoP 的稳定性、金属原子修饰的 MoP 上 N2 的吸附能和键长，我们选择 Mn 和 V 作为两个候选者，并详细研究了 Mn-MoP 和 V-MoP 的可能氮气还原反应（NRR）途径。我们的结果表明，Mn-MoP 和 V-MoP 的能量变化值分别为 0.95 eV 和 0.65 eV，其中第一个加氢步骤是潜在的限速步骤。Mn-MoP 可以有效地抑制*H 吸附，并减少析氢反应（HER）与 NRR 的竞争；而 V-MoP 则不能。因此，Mn-MoP 是一种更好的催化剂，可以实现氮气还原反应。总的来说，这项工作朝着过渡金属磷化物的 NRR 可能性迈出了一步，并为实验提供了一些重要的见解和指导。
