In Situ Exsolved Metal Nanoparticles: A Smart Approach for Optimization of Catalysts

Heterogeneous supported metal nanoparticles (NPs) are extensively applied in a variety of chemical and energy conversion processes. Traditionally, these catalysts are prepared by deposition methods. However, they usually show wide ranging size distributions and are easily subject to poisoning and coarsening or agglomeration during the reactions. Alternatively, the time and cost-effective in situ exsolution strategy has successfully addressed the above drawbacks and is able to produce finer and more evenly distributed metal NPs even at relatively low metal loading. Endowed by their socketed nature, the exsolved metal NPs possess excellent operational stabilities as well as great catalytic activities. Moreover, these exsolved metal NPs are smart and can be regenerated upon redox treatments, further extending the lifetime of catalysts. This review presents a general idea in facilitating the degree of exsolution from various oxide substrates by summarizing the recent advances in the exsolution related studies and research outputs with a special emphasis on the understanding of the thermodynamical roles of different experimental parameters.