Ultrafine metal nanoparticles isolated on oxide nano-islands as exceptional sintering-resistant catalysts

Abstract

Ultrafine nanoparticles (NPs) have attracted extensive research interest, especially in heterogeneous catalysis. However, the inherent sintering propensity of NPs has been a major obstacle to their catalytic stability. Here we report an isolation strategy to preserve highly dispersed ultrafine NPs under extremely harsh conditions. Oxide nano-islands were grafted between the catalyst support and metal NPs, serving as a general approach by following a charge attraction principle. Specifically, LaOx nano-islands were ideally suited for stabilizing Ru NPs among the synthetic library, exhibiting strong adhesion to minimize the chemical potential and disconnect the sintering path. Thus, ultrafine Ru NPs in Ru/LaOx–SiO2 were isolated, maintaining a mean size of 1.4 nm in CO- and H2-rich atmosphere during efficient catalysis for methane dry reforming at 800 °C for 400 h. This isolation strategy has proved effective for many other metals on various supports, paving a practical way for the design of sintering-resistant catalysts. An isolation strategy is presented to improve the stability of metal nanoparticles by grafting oxide nano-islands between the support and the nanoparticles. This enhances sintering resistance, with the mean size of the nanoparticles maintained at 1.4 nm after 400 h of catalytic dry reforming of methane.