Tailored Ru Catalysts on Gamma Alumina: Enhancing Polyethylene Hydrogenolysis for High-Value Liquid Fuel Production

Nowadays, plastics are increasingly used in the activities of our daily lives, including packaging in different food and brewing companies, cosmetics, pharmaceuticals, and other production sectors. Plastics are produced through the biochemical process of polymerization or polycondensation. The late use of the generated plastic waste has many adverse effects on the environment if it is treated or managed improperly. Herein, a novel ruthenium (Ru) supported on gamma alumina (Ru/γ-Al2O3) catalyst was developed as an efficient catalyst to boost polyethylene (PE) hydrogenolysis to produce high-value liquid fuel. Under mild reaction conditions (240 °C, 2.0 MPa, 12 h), the catalytic performance of Ru/γ-Al2O3 with different carrier forms and Ru contents was studied (catalyst/PE = 1:1). The results revealed that the 1Ru/γ-Al2O3 nanosheet (NS) catalyst, containing approximately 1 wt % Ru, exhibited remarkable performance in PE hydrogenolysis. It achieved a high PE conversion of 97.50% and yielded a significant amount of liquid fuel (C5–C21) at 70.65%, with a 75.65% selectivity of liquid fuel (C5–C21). The enhancement in performance is primarily attributed to the abundance of surface-exposed medium acidic sites, coupled with the presence of suitably electron-deficient Ru species and the highly dispersed Ru induced by metal-support interactions. The findings provide valuable insights for the design of catalysts aimed at improving the yield of high-value liquid fuels in the hydrogenolysis process of PE plastics.