Zeolite-encapsulated Cu nanoparticles with enhanced performance for ethanol dehydrogenation

The selective dehydrogenation of ethanol to acetaldehyde is one of the pivotal reactions for biomass valorization, wherein the well-defined and robust Cu-based solid catalysts are highly desired for potential practical application. Herein, ultra-small Cu metal nanoclusters (∼1.8 nm), encapsulated inside Silicate-1 (S-1), have been successfully fabricated by an in-situ approach. The as-synthesized [email protected] catalyst shows a near quantitative ethanol conversion, a good acetaldehyde selectivity up to ∼90 %, and more importantly an excellent stability with no apparent deactivation even after a TOS of 110 h in the continuous dehydrogenation of ethanol to acetaldehyde at 523 K. Comprehensive and thorough characterization studies reveal that the spatial constraint environment of the zeolite could not only efficiently restrict the movements of Cu entities, which thus prevents the metal sintering during catalysis, but also induce a predominant amount of well-retained Cu+ species (up to ∼70 %) that play an essential role for the enhanced performance.