Mild Hydrogenation of α-Pinene Catalyzed by Ru Nanoparticles Loaded on Boron-doped Amphiphilic Core-Shell Mesoporous Molecular Sieves

Graphical Take core ! Highly dispersed and stable Ru nanoparticle catalysts loaded on boron-doped amphiphilic, core-shell, mesoporous molecular sieves are successfully prepared and used to catalyze the hydrogenation of α-pinene to cis -pinane with an excellent catalytic activity, high selectivity, and good recyclability, in mild experimental conditions given that every nanocomposite is equivalent to a microreactor. Highly dispersed and stable catalysts comprising Ru nanoparticles supported on boron-doped amphiphilic core-shell mesoporous molecular sieves (MMS−C@MMS−NH 2 /B/Ru) with alkyl-modified hydrophobic silica core and NH 2 -functionalized hydrophilic silica shell are successfully prepared for use in hydrogenation of α-pinene for the first time. Dodecyl-modified MMS−C 12 @MMS−NH 2 /B/Ru exhibits the best catalytic activity under mild hydrogenation conditions. The abundant −NH 2 functional groups on the molecular sieve surface and their amphipathy allow the sieves to facilitate attachment of more Ru nanoparticles, and to simplify their dispersion in the water-organic reaction medium. Moreover, B-doped molecular sieves may adjust their acidity to meet the needs of α-pinene hydrogenation. Under mild reaction conditions (25 °C, 1 MPa H 2 , and 1 h), α-pinene can be completely converted with 99 % selectivity to cis -pinane, because every nanocomposite is equivalent to a microreactor. The catalytic activity does not change much over 5 cycles, indicating that Ru nanoparticles are stably loaded on the molecular sieves.