Metal–carbon composites have a wide application, such as sensing, electrode and catalytic materials. The interplay between the metal nanoparticles and carbon substrate has attracted significant attention. Recent studies show that the rich varieties of carbon microstructures can help to create unexpected reaction sites on metal particle that promote the activity and stability. However, as the supported nanoparticle is dynamic in reaction conditions, how this dynamic behavior is influenced by the support remains elusive. Herein, we present a quantitative analysis on the structural versatility of nanocatalysts using the stochastic surface walking (SSW) global optimization method (J. Chem. Theory Comput. 2013, 9, 1838; J. Chem. Theory Comput. 2013, 9, 3252). Theory shows that the configuration space of a nanocatalyst is sensitive to the nanoparticle environment, and affects its activity and stability. We reveal that confined metal nanoparticles are structurally more flexible at low temperatures but less likely to melt at high temperatures. By investigating the O2 interaction with Pt15 cluster inside and outside the CNT, we find that the low temperature structure versatility facilitates the in situ creation of favourable reaction sites and thus maintain the catalyst activity of O2 dissociation. The decrease of the population for the liquid-like structures (largely disordered) offers the higher stability of confined nanocatalyst. This finding, together with the current knowledge on crystalline surfaces, provides a new perspective to design high performance catalysts with dynamic structures.

Dynamic structures and catalytic properties of platinum nanoparticle in carbon nanotube

253rd National Meeting (2017)

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