反应驱动的Rh-Pd和Pt-Pd核心外纳米颗粒的重组
Feng Tao1, Michael E Grass, Yawen Zhang
1Materials Sciences and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Science (New York, N.Y.)
|October 11, 2008
概括
双金属纳米粒子催化剂表现出不同的稳定性. -纳米颗粒通过氧化/减少改变组成,而-纳米颗粒保持稳定,突出可调节的催化剂结构.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 表面化学 表面化学
背景情况:
- 双金属纳米粒子在异质催化中至关重要.
- 纳米颗粒中的金属分离可以受到反应环境的影响.
- 了解纳米粒子重组是催化剂设计的关键.
研究的目的:
- 研究Rh{0.5}Pd{0.5}和Pt{0.5}Pd{0.5}纳米粒子催化剂的现场结构和组成变化.
- 在各种反应条件下比较不同双金属纳米粒子系统的稳定性和反应.
- 在催化反应期间探索双金属纳米粒子结构的可调性.
主要方法:
- 在位X射线光电子光谱 (XPS) 在近环境压力下.
- 核心外Rh{0.5}Pd{0.5}和Pt{0.5}Pd{0.5}纳米粒子催化剂的研究.
- 暴露于氧化,还原和催化反应条件 (NO,O2,CO,H2) 的情况.
主要成果:
- - (Rh(0.5) Pd(0.5)) 纳米粒子在组成和化学状态上表现出显著和可逆的变化.
- - (Pt{0.5}-Pd{0.5}) 纳米粒子没有显示构成金属原子的实质性分离.
- 在相同的条件下,在两个双金属系统中观察到不同的重组和化学反应.
结论:
- 双金属纳米粒子催化剂的行为高度依赖于它们的组成.
- -纳米粒子显示出动态重组,提供可调节的催化性能.
- -纳米粒子在研究条件下表现出更大的结构稳定性.
- 这些发现强调了双金属纳米粒子结构在催化中的灵活性和可调性.
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