A review of the catalytic preparation of mesophase pitch

Because of its high purity and excellent orientation, mesophase pitch is a superior precursor for high-performance carbon materials. However, the preparation of top-notch mesophase pitch faces challenges. Catalytic polycondensation at low temperatures is more favorable for synthesizing mesophase pitch, because it circumvents the high-temperature free radical reaction of other thermal polycondensation approaches. The reaction is gentle and can be easily controlled. It has the potential to significantly improve the yield of mesophase pitch and easily introduce naphthenic characteristics into the molecules, catalytic polycondensation is therefore a preferred method of synthesizing highly spinnable mesophase pitch. This review provides a synopsis of the selective pretreatment of the raw materials to prepare different mesophase pitches, and explains the reaction mechanism and associated research advances for different catalytic systems in recent years. Finally, how to manufacture high-quality mesophase pitch by using a catalyst-promoter system is summarized and proposed, which may provide a theoretical basis for the future design of high-quality pitch molecules.