A copper decorated porphyrin-based porous organic polymer: Evaluation in the oxidation of lignin model compounds

A novel porous organic polymer containing porphyrin units was synthesized and decorated with copper to produce the metallated POP, Cu-TriPOP. The native POP, Nat-TriPOP and metal-decorated Cu-TriPOP exhibited BET surface areas of 595 m2/g and 373 m2/g, respectively. Excellent thermal stability up to 300 °C was observed by thermogravimetric analysis. Transmission electron microscopy (TEM) showed a sea urchin/bush-like morphology. The metal-decorated POP, Cu-TriPOP, was evaluated in the oxidation of veratryl alcohol and other related substrates. Excellent catalytic performance was achieved with conversions of around 80%. The addition of ascorbic acid, a well-known radical scavenger, significantly reduced the activity, suggesting that a radical mechanism is most likely operative. In addition, excellent catalyst recovery and recyclability were achieved for up to five cycles with minimal decrease in activity.