Real Time Indirect Nanoplasmonic in situ Spectroscopy of Catalyst Nanoparticle Sintering

Catalyst deactivation by sintering significantly reduces productivity and energy efficiency of the chemical industry, and the effectiveness of environmental cleanup processes. It also hampers the introduction of novel energy conversion devices such as fuel cells. The use of experimental techniques that allow the scrutiny of sintering in situ at high temperatures and pressures in reactive environments is a key to alleviate this situation. Today such techniques are, however, lacking. Here we demonstrate by monitoring the sintering kinetics of a Pt/SiO2 model catalyst under such conditions in real time that indirect nanoplasmonic sensing (INPS) has the potential to fill this gap. Specifically, we show an unambiguous correlation between the optical response of the INPS sensor and catalyst sintering. The obtained data are analyzed by means of a kinetic model accounting for the particle-size dependent activation energy of Pt detachment. Ostwald ripening is identified as the main sintering mechanism.

Published in: ACS Catalysis

Date: 2012-01-03

Authors: Elin M. Larsson, Julien Millet, Stefan Gustafsson, Magnus Skoglundh, Vladimir P. Zhdanov, Christoph Langhammer