Abstract: A macroporous alumina catalyst loaded with La was prepared. In a miniature reaction kettle, using nylon 6 as the raw material and deionized water as the solvent, the catalytic depolymerization performance of nylon 6 was studied. The effects of reaction temperature, reaction time, catalyst dosage, and other factors on the depolymerization of nylon 6 were examined. The structure and properties of the catalyst, as well as the depolymerization products, were characterized and analyzed. The results show that the macroporous alumina loaded with La exhibits good catalytic performance. Under optimal conditions—reaction temperature of 240 °C, reaction time of 600 min, and catalyst dosage of 1% of the mass of nylon 6—the depolymerization effect was the best, with a nylon 6 conversion rate of 72.22% and a caprolactam yield of 30.03%.

Key words: nylon-6, depolymerization, caprolactam, macroporous alumina