Efficient Catalytic Activity of Ti3C2Tx MXene for Polyester Synthesis

Polyethylene terephthalate (PET) is one of the most widely used polymers for beverage packaging and fibers, with antimony-based catalysts currently dominating its synthesis. However, concerns about potential safety hazards associated with antimony leaching necessitate the development of environmentally benign catalysts free from heavy metals. In this work, we report the first-time utilization of Ti3C2Tx MXene as a polycondensation catalyst of PET. The intrinsic viscosity of Ti3C2Tx MXene-catalyzed PET could reach 0.78 dL/g within 2.1 h, which demonstrated a superior catalytic efficiency compared to antimony trioxide (Sb2O3). Moreover, Ti3C2Tx MXene exhibited a satisfactory performance not only in PET synthesis but also in the production of polypropylene terephthalate (PPT) and polybutylene terephthalate (PBT), thereby confirming its universality in polyester catalysis. The catalytic activity of Ti3C2Tx MXene in polycondensation reactions was attributed to the presence of strong Lewis acid sites, as supported by surface examinations and computational studies. Notably, Ti3C2Tx MXene-catalyzed PET exhibited satisfied crystallizability, as confirmed by the short crystallization half-time of only 6.9 s at 185 °C, signifying a high crystallization rate. This work highlights the potential applications of this thriving 2D material in polyester catalysis and, more importantly, provides a new perspective for the exploration and design of efficient and environmentally friendly catalyst/nucleation agents for polyester synthesis.