在Au/TiC上提奥芬的脱硫 (001):Au-C相互作用和电荷极化
José A Rodriguez1, Ping Liu, Yoshiro Takahashi
1Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA. rodrigez@bnl.gov
Journal of the American Chemical Society
|June 18, 2009
概括
在碳化 (TiC) 表面上的金纳米颗粒显著提高了水解硫化. 这种Au/TiC系统增强了蒂奥芬结合和解离,性能优于传统的去除硫的催化剂.
科学领域:
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
- 催化剂是一种催化剂.
背景情况:
- 蒂奥芬在TiC(001) 上的吸附能力较弱,吸附率低于200K.
- 提奥芬通过硫与TiC的结构变化最小,通过硫与TiC中心结合.
- TiC ((001) 和Au ((111) 单独表现出较差的脱硫性能.
研究的目的:
- 研究蒂奥芬与TiC(001) 和Au/TiC(001) 表面的相互作用.
- 评估Au/TiC(001) 系统的水解硫活性.
- 了解黄金-碳相互作用在催化活性中的作用.
主要方法:
- 光辐射光谱学. 光辐射光谱学.
- 第一个原则 密度函数 (DF) 计算.
主要成果:
- Au/TiC(001) 显示出比传统的Ni/MoS(x) 催化剂更高的水解硫活性.
- Au-TiC相互作用使Au周围的电子密度两极分化,增强其反应性.
- 黄金纳米粒子增加了硫结合能,并促进了H(2) 解离.
- H(2) 在与TiC(001) 接触的黄金集群上自发分离.
- 在Au/TiC(001) 上的提奥芬吸附能量比TiC(001) 或Au(111) 上的0.45-0.65 eV大.
- 烯采用eta(5) 配置,延长C-S键约0.2 Å.
结论:
- Au/TiC(001) 系统显示出显著的脱硫潜力.
- 黄金纳米粒子对于通过改进的结合和激活来增强催化活性至关重要.
- 黄金和TiC之间的协同作用是有效去除硫的关键.
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