Stochastic Noise in Single-Nanoparticle Catalysis

Nanoparticle-based catalysts exhibit considerable complexity and heterogeneity. New light can be shed into these aspects by probing catalysis on the level of single nanoparticles. Here, we monitor on individual Ag nanoparticles plasmon-excitation-driven CO2 reduction and formation of multicarbon species on the Ag surface. The measurements show that catalytic activities and selectivities are variable from one nanoparticle to another, an effect that would typically be attributed to structural and morphological differences between nanoparticles. However, the nanoparticle-to-nanoparticle variations observed here are accompanied by temporal fluctuations in the catalytic activity. We infer that the variation captures, in addition to static heterogeneities in the nanoparticle-based catalyst, noise from inherent stochasticity of catalytic events occurring on the nanoparticle surface. Such noise can be an inadvertent source of variations observed in single-nanoparticle, single-molecule studies of catalysis.