Zhang Yue, Cao Xinrui, Cao Zexing
State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Department of Physics and Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen University, Xiamen 361005, China.
ACS Appl Mater Interfaces. 2022 Aug 10;14(31):35844-35853. doi: 10.1021/acsami.2c09813. Epub 2022 Jul 29.
Graphitic carbon nitride (g-CN) is regarded as a promising potent photoelectrocatalyst for CO reduction. Here, extensive first-principles calculations and ab initio molecular dynamics (AIMD) simulations are performed to systematically explore the structural and electronic properties of nonprecious metal single-atom-embedded graphitic s-triazine-based CN (M@gt-CN, M = Mn, Fe, Co, Ni, Cu, and Mo) monolayer materials and their catalytic performances as the single-atom catalysts (SACs) for CO hydrogenation to HCOOH, CO, and CHOH. It is found that the atomically dispersed non-noble metal Mn, Fe, Co, and Mo sites anchored on gt-CN can efficiently activate both H and CO, and their coadsorbed state serves as a precursor to the hydrogenation of CO to different C1 products. Among these SACs (M@gt-CN, M = Mn, Fe, Co, and Mo), Co@gt-CN was predicted to have the best catalytic performance for CO hydrogenation to C1 products, although their mechanistic details are somewhat different. The predicted energy barriers of the rate-determining steps for the conversion of CO into HCOOH, CO, and CHOH on Co@gt-CN are 0.58, 0.67, and 1.19 eV, respectively. The desorption of products is generally energy-demanding, but it can be facilitated remarkably by the subsequent adsorption of H, which regenerates M@gt-CN for the next catalytic cycle. The present study demonstrates that the catalytic performance of gt-CN can be well regulated by embedding the non-noble metal single atom, and the porous gt-CN is nicely suited for the construction of high-performance single-atom catalysts.
石墨相氮化碳（g-CN）被认为是一种很有前景的用于CO还原的高效光电催化剂。在此，我们进行了广泛的第一性原理计算和从头算分子动力学（AIMD）模拟，以系统地探索非贵金属单原子嵌入的基于石墨s-三嗪的CN（M@gt-CN，M = Mn、Fe、Co、Ni、Cu和Mo）单层材料的结构和电子性质，以及它们作为将CO加氢生成HCOOH、CO和CHOH的单原子催化剂（SACs）的催化性能。研究发现，锚定在gt-CN上的原子分散的非贵金属Mn、Fe、Co和Mo位点能够有效地活化H和CO，它们的共吸附状态是CO加氢生成不同C1产物的前驱体。在这些SACs（M@gt-CN，M = Mn、Fe、Co和Mo）中，尽管其机理细节有所不同，但预测Co@gt-CN对CO加氢生成C1产物具有最佳的催化性能。在Co@gt-CN上，CO转化为HCOOH、CO和CHOH的速率决定步骤的预测能垒分别为0.58、0.67和1.19 eV。产物的脱附通常需要能量，但随后的H吸附可以显著促进脱附，从而使M@gt-CN再生以进行下一个催化循环。本研究表明，通过嵌入非贵金属单原子可以很好地调节gt-CN的催化性能，多孔gt-CN非常适合构建高性能的单原子催化剂。
