Frustrated Lewis Pairs‐Engineered Boron‐Doped Carbon Nitride: An Efficient Metal‐Free Catalyst for the Depolymerization of Polyethylene Terephthalate

The development of efficient and sustainable catalytic systems for plastic depolymerization is crucial for advancing a circular economy. Herein, we report the construction of boron-doped carbon nitride (B-CN) as a metal-free catalyst featuring frustrated Lewis pairs (FLPs) for the efficient glycolysis and methanolysis of polyethylene terephthalate (PET). The boron doping creates Lewis acid sites adjacent to intrinsic Lewis basic nitrogen sites, which synergistically activate the carbonyl group of PET and promote alcohol deprotonation. The optimized catalyst achieves over 90% yields of the BHET and DMT monomer and exhibits broad applicability to the depolymerization of various commercial PET wastes. The catalyst also exhibits exceptional catalytic stability, with no significant performance degradation over 10 consecutive cycles. This work pioneers a green and versatile FLPs-based metal free catalytic strategy for the chemical recycling of plastics.