Sintering of catalytic metal nanoparticles under exothermic conditions in a continuous stirred tank reactor

Abstract

Academic studies of sintering of supported metal nanoparticles usually imply that the system temperature is constant and the growth of the average nanoparticle radius and decrease of dispersion or activity can be described by the power-law equations. In catalytic applications, the sintering typically occurs in reactors under exothermic conditions at high temperatures, and the sintering-related loss of the catalyst activity may result in decrease of temperature, which in turn may reduce the rate of sintering. Focusing on catalytic conversion in a continuous stirred tank reactor, I show that in the presence of this negative feedback the power-law equations can be used as well by introducing the apparent exponent which is appreciably larger than that measured or predicted by the conventional models of sintering at constant temperature.