Sorbitol-derived carbon overlayers encapsulated Cu nanoparticles on SiO2: Stable and efficient for the continuous hydrogenation of ethylene carbonate

Summary An ultrastable and efficient Cu@C/SiO 2 nanocatalyst was fabricated for the hydrogenation of ethylene carbonate, in which Cu nanoparticles are encapsulated by sorbitol-derived graphitized carbon overlayers. During the calcination of Cu-sorbitol/SiO 2 precursors under N 2 atmosphere, sorbitol decomposed to CO and CO 2 . The in situ generated CO not only reduced Cu 2+ to Cu 0 /Cu + , but also formed graphitized carbon overlayers on the Cu surface via the disproportionation of CO. The Cu@C/SiO 2 catalyst exhibited superior catalytic performance (91% MeOH yield and 43.6 h −1 TOF) at a H 2 /EC molar ratio of 20. Of particular note, the Cu@C/SiO 2 catalyst showed remarkable long-term stability during 736 h time-on-stream test without any deactivation. The graphitized carbon overlayers on the surface of Cu nanoparticles not only functioned synergistically with the surface Cu 0 /Cu + sites to promote the EC hydrogenation but also suppressed the sintering of Cu nanoparticles. Furthermore, the interaction of Cu nanoparticles and graphitized carbon overlayers stabilized the surface Cu + /(Cu 0 +Cu + ) ratio.