Li Yameng, Li Lei, Huang Rao, Wen Yuhua
Department of Physics, Xiamen University, Xiamen 361005, China.
Nanoscale. 2021 Sep 17;13(35):15002-15009. doi: 10.1039/d1nr04652g.
As an emerging family of two-dimensional (2D) materials, transition metal borides (MBenes) have attracted increasing interest due to their potential applications in electrochemistry, especially electrocatalysis. In this work, we addressed six MB (M = Sc, Ti, V, Cr, Mo and W) monolayers as catalysts to explore their electrocatalytic activity for the nitrogen reduction reaction (NRR) using first-principles calculations. Our results demonstrated that N molecules could be strongly adsorbed on these MB monolayers to provoke the NRR process. Furthermore, we examined five possible catalytic reaction pathways of the NRR, , the alternating, distal, and three mixed pathways, on the MB monolayers with N adsorption (both side-on and end-on) configurations, and screened out three highly efficient NRR catalysts: VB, CrB, and MoB monolayers with the onset potential of -0.396, -0.277, and -0.403 V, respectively. By comparison of the limiting potentials, the most effective reaction pathways of the NRR were ascertained to be the alternating pathway on the VB monolayer with the end-on configuration and the mixed I pathway on the CrB monolayer with the end-on configuration and on the MoB monolayer with the side-on configuration. Our work sheds light on the electrocatalytic mechanisms of the NRR on 2D MBenes, and provides a theoretical foundation for developing highly efficient MBene electrocatalysts for the NRR.
作为二维（2D）材料中的一个新兴家族，过渡金属硼化物（MBenes）因其在电化学，尤其是电催化方面的潜在应用而引起了越来越多的关注。在这项工作中，我们使用第一性原理计算，将六种MB（M = Sc、Ti、V、Cr、Mo和W）单层作为催化剂，以探索它们对氮还原反应（NRR）的电催化活性。我们的结果表明，N分子可以强烈吸附在这些MB单层上，从而引发NRR过程。此外，我们研究了在具有N吸附（侧端吸附和端端吸附）构型的MB单层上NRR的五种可能催化反应途径，即交替途径、远端途径和三种混合途径，并筛选出三种高效的NRR催化剂：VB、CrB和MoB单层，其起始电位分别为-0.396、-0.277和-0.403 V。通过比较极限电位，确定NRR最有效的反应途径是端端构型的VB单层上的交替途径以及端端构型的CrB单层和侧端构型的MoB单层上的混合I途径。我们的工作揭示了二维MBenes上NRR的电催化机制，并为开发用于NRR的高效MBene电催化剂提供了理论基础。
