A novel type of catalytic static mixers with rectangular cross-section coated with Pd/Al2O3 has been developed. The catalytic mixers, produced by additive manufacturing and coated with the metal catalyst, have shown excellent catalytic performance for continuous flow hydrogenation of nitroaromatics. The heterogeneous catalyst is highly stable. No loss of catalytic performance was observed after long periods of activity and ICP-MS measurements determined that essentially no Pd or Al leaches from the reactor. The rectangular cross-section reactor is readily scalable. The process developed has been showcased for the synthesis of the key intermediate of the medicine tizanidine.

• Center for Continuous Flow Synthesis and Processing (CCFLOW), Research Center Pharmaceutical Engineering GmbH (RCPE)
• University of Graz
• CSIRO Manufacturing

• Intermediate

1. 3D-printed static mixer
2. hydrogenation
3. Intermediate
4. nitroaromatic
5. Pd/Al2O3
6. Research Article
7. tizanidine