Newton Mark A, Belver-Coldeira Carolina, Martínez-Arias Arturo, Fernández-García Marcos
The European Synchrotron Radiation Facility, 6, Rue Jules Horowitz, BP-220, Grenoble, France.
Nat Mater. 2007 Jul;6(7):528-32. doi: 10.1038/nmat1924. Epub 2007 May 27.
Understanding and improving the behaviour of supported precious-metal catalysts for a vast array of environmentally and economically important processes is a central area of research in catalysis. The removal of toxic gases such as CO and NO, without forming others (such as N(2)O), is particularly important. By combining energy-dispersive extended X-ray absorption fine-structure spectroscopy with a vibrational spectroscopy (infrared) and mass spectrometry, at high time resolution, in a single in situ experiment, we dynamically observe and quantify CO-, and subsequent NO-, induced size and shape changes of Pd nanoparticles during CO/NO cycling. In doing so we demonstrate a novel, non-oxidative redispersion (for example, an increase in metal surface area) mechanism, and suggest a model to bridge the structural and reactive functions of supported Pd catalysts.
理解并改善负载型贵金属催化剂在众多环境和经济重要过程中的行为，是催化领域的核心研究方向。去除诸如一氧化碳和一氧化氮等有毒气体，同时不生成其他气体（如一氧化二氮），尤为重要。通过在单次原位实验中，以高时间分辨率将能量色散扩展X射线吸收精细结构光谱与振动光谱（红外）和质谱相结合，我们动态观察并量化了在一氧化碳/一氧化氮循环过程中，一氧化碳以及随后的一氧化氮诱导的钯纳米颗粒尺寸和形状的变化。在此过程中，我们展示了一种新型的非氧化再分散（例如金属表面积增加）机制，并提出了一个模型来连接负载型钯催化剂的结构和反应功能。
