Real Time Indirect Nanoplasmonic in Situ Spectroscopy of Catalyst Nanoparticle Sintering
journal contributionposted on 03.02.2012, 00:00 by Elin M. Larsson, Julien Millet, Stefan Gustafsson, Magnus Skoglundh, Vladimir P. Zhdanov, Christoph Langhammer
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 the Pt detachment. Ostwald ripening is identified as the main sintering mechanism.