Dynamic in situ observation of rapid size and shape change of supported Pd nanoparticles during CO/NO cycling.
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.
Newton
Mark A
MA
The European Synchrotron Radiation Facility, 6, Rue Jules Horowitz, BP-220, Grenoble, France. newton@esrf.fr
Belver-Coldeira
Carolina
C
Martínez-Arias
Arturo
A
Fernández-García
Marcos
M