An electronic perturbation in TiC supported platinum monolayer catalyst for enhancing water-gas shift performance: DFT study
An electronic perturbation in TiC supported platinum monolayer catalyst for enhancing water-gas shift performance: DFT study
复制标题
用于增强水煤气变换性能的 TiC 负载铂单层催化剂中的电子扰动：DFT 研究
DOI：
10.1088/1361-648x/ab1a13
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Zongxian Yang
中科院分区：
文献类型：
--
作者：
Yan Wang;Xilin Zhang;Zhaoming Fu;Zhansheng Lu;Zongxian Yang
用自旋自由密度泛函理论方法研究了TiC(0 0 1)担载的铂单分子层催化剂(PtML/TiC(0 0 1))上的水煤气变换(WGS)反应行为。重要的是，我们发现PtML/TiC(0 0 1)体系在费米能级附近表现出比铂(1 1 1)低得多的铂5d态密度，单层铂原子在与TiC(0 0 1)载体接触时发生电子微扰，这将极大地提高担载铂原子的WGS活性。我们的计算清楚地表明，主要的反应路径遵循包含关键COOH中间体的羧基机理，而不是共同的氧化还原机理。此外，通过详细的比较，结果表明，单层铂原子与TiC(0 0 1)载体之间的强相互作用使PtML/TiC(0 0 1)成为低温WGS反应的高活性催化剂。遵循Bruix等人提出的路线(2012 J.Am化学。SoC。134 8968-74)，揭示了金属/碳化物体系中金属-载体相互作用的正效应。
The water–gas shift (WGS) reaction behaviors over the TiC (0 0 1) supported Pt monolayer catalyst (Pt ML/TiC (0 0 1)) are investigated by using the spin-unrestricted density functional theory calculations. Importantly, we find that the Pt ML/TiC (0 0 1) system exhibits a much lower density of Pt-5d states nearby the Fermi level compared with that for Pt (1 1 1), and the monolayer Pt atoms undergo an electronic perturbation when in contact with TiC (0 0 1) support that would strongly improve the WGS activity of supported Pt atoms. Our calculations clearly indicate that the dominant reaction path follows a carboxyl mechanism involving a key COOH intermediate, rather than the common redox mechanism. Furthermore, through the detailed comparisons, the results demonstrate that the strong interactions between the monolayer Pt atoms and TiC (0 0 1) support make Pt ML/TiC (0 0 1) a highly active catalyst for the low-temperature WGS reaction. Following the route presented by Bruix et al (2012 J. Am. Chem. Soc. 134 8968–74), the positive effect derived from strong metal-support interaction in the metal/carbide system is revealed.