Cyclic Extrusion Synthesis of Mesoporous Carbon-Supported Metal
Catalysts for Selective Hydrogenation
Abstract
The mesoporous carbon-supported metal catalysts are important materials
in heterogeneous catalysis. From the standpoint of process
intensification, the current synthesis methods still suffer from several
issues, such as the excessive use of toxic solvents, the time-consuming
self-assembly process, and the difficulty of continuous production.
Herein, we report a solvent-free and continuous route to synthesize
mesoporous carbon-supported metal catalysts. Interestingly, the use of
cyclic extrusion could promote the mixing, coordination, and assembly of
catalyst precursors (tannin-metal salts-additives) by shearing and
squeeze force. The as-made mesoporous carbon-supported nickel showed
high surface areas (up to 512m2g-1), narrow pore size distribution
(~10 nm), and good performance in the selective
hydrogenation of nitrobenzene to aniline (Conv.>99%;
Sel.>99%). In addition, the fluid property of catalyst
precursors and the geometry of the twin-screw extrusion channel were
studied, and the essence of this cyclic extrusion process is also
discussed.