了解MoO3-促进合成气转化为酒精的Rh催化剂的结构-属性关系
Arun S Asundi1, Adam S Hoffman2, Pallavi Bothra1,3
1Department of Chemical Engineering , Stanford University , Stanford , California 94305 , United States.
Journal of the American Chemical Society
|November 15, 2019
概括
三氧化物 (MoO3) 促进的 (Rh) 纳米粒子创建了一个新的催化剂结构. 这种结构显著提高了将合成气转化为高氧化物的催化性能,使反应速率提高了66倍.
科学领域:
- 催化剂
- 材料科学
- 表面化学
背景情况:
- (Rh) 基催化剂对于直接将合成气转化为高氧化物是有效的.
- 了解Rh金属氧化物催化剂的结构和促进作用对于优化性能至关重要.
研究的目的:
- 研究MoO3促进的Rh纳米粒子的结构.
- 阐明MoO3在提高催化活性和选择性的作用,以提高氧化物产量.
主要方法:
- 使用原子层沉积 (ALD) 进行精确的MoO3Rh纳米颗粒的原子控制合成.
- 在现场X射线吸收光谱 (XAS) 用于在反应条件下确定表面结构.
- 密度函数理论 (DFT) 的计算,以了解促进物-Rh相互作用和反应机制.
主要成果:
- 一个新的催化剂结构被形成,其中 (Mo) 替代了Rh表面.
- 在反应条件下,Mo-替代的Rh表面表现出Mo-OH物种.
- 观察到翻转频率增加了66倍,氧化物产量增加.
结论:
- 在Rh表面的Mo替代是提高催化性能的关键.
- 在Rh表面的Mo-OH物种促进CO分离并稳定甲醇合成途径.
- 来自Mo-OH场所的溢出增强了中间体的化,提高了整体反应速率.
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