Possibilities of the Quantitative Comparison of Catalytic Capacity in Autocatalytic Processes of Palladium-Containing Nanocatalysts

Abstract

When studying the nanocrystalline state, in some cases, an increase in functional activity is observed with an increase in the size of nanoparticles. In this case, the most active atoms are situated on the faces and have a higher coordination in comparison with the atoms on the tops and the edges. One of the explanations for this phenomenon is the formation of hypercycles due to the occurrence of autocatalytic processes. For oscillatory processes inherent in autocatalysis, when the parameters of a nonequilibrium process change over time, it is difficult to apply traditional methods of processing the results of analytical studies. In this regard, it is necessary to develop a methodology for a comparative study of short-term parameters of processes on the same scale, highlighting the main ones and eliminating insignificant and random ones, such as the phase shift at the beginning of self-oscillations or time-localized deviations from activity. This paper presents the results of such a study on the example of palladium-containing nanosystems in the reaction of low-temperature oxidation of CO. It is shown that the study of the behavior of nanocatalysts during the formation of hypercycles is informative using the calculated generalized parameters of the process