No abstract

Highly dispersed and stable catalysts comprising Ru nanoparticles supported on boron-doped amphiphilic core-shell mesoporous molecular sieves (MMSÀ C@MMSÀ 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 MMSÀ C 12 @MMSÀ NH 2 /B/Ru exhibits the best catalytic activity under mild hydrogenation conditions. The abundant À 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 waterorganic 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.

A multifunctional nanomaterial (Fe3O4@SiO2@CX@NH2) comprising a magnetic core, a silicon protective interlayer, and an amphiphilic silica shell is successfully prepared. Ru nanoparticles catalyst loaded on Fe3O4@SiO2@CX@NH2 is used in hydrogenation of α‐pinene for the first time. The novel nanomaterial with amphipathy can be used as a solid foaming agent to increase gas–liquid–solid three‐phase contact and accelerate the reaction. Under the mild conditions (40 °C, 1 MPa H2, 3 h), 99.9% α‐pinene conversion and 98.9% cis‐pinane selectivity are obtained, which is by far the best results reported. Furthermore, the magnetic nanocomposite catalyst can be easily separated by an external magnet and reused nine times with high selectivity maintaining.