Site-Selective Polyolefin Hydrogenolysis on Atomic Ru for Methanation Suppression and Liquid Fuel Production

Abstract

Catalytic hydrogenolysis of end-of-life polyolefins can produce value-added liquid fuels and therefore holds great promises in plastic waste reuse and environmental remediation. The major challenge limiting the recycling economic benefit is the severe methanation (usually >20%) induced by terminal C–C cleavage and fragmentation in polyolefin chains. Here, we overcome this challenge by demonstrating that Ru single-atom catalyst can effectively suppress methanation by inhibiting terminal C–C cleavage and preventing chain fragmentation that typically occurs on multi-Ru sites. The Ru single-atom catalyst supported on CeO 2 shows an ultralow CH 4 yield of 2.2% and a liquid fuel yield of over 94.5% with a production rate of 314.93 g fuels g Ru −1 h −1 at 250 °C for 6 h. Such remarkable catalytic activity and selectivity of Ru single-atom catalyst in polyolefin hydrogenolysis offer immense opportunities for plastic upcycling.

Review on Catalytic Depolymerization of Polyolefin Waste by Hydrogenolysis: State-of-the-Art and Outlook

“…The products obtained were gaseous hydrocarbon (C 1 –C 4 ), liquid fuel (C 5 –C 21 ), and wax (C 22 –C 45 ). Another approach adopted for the suppression of methanation during the hydrogenolysis of polyolefins using a single ruthenium atom was reported by Chu et al (Table , entry 13) . In their findings, they succeeded in maximizing the liquid hydrocarbon yield to 94.5% by lowering the methane yield to 2.2%.…”

“…Another approach adopted for the suppression of methanation during the hydrogenolysis of polyolefins using a single ruthenium atom was reported by Chu et al (Table 1, entry 13). 104 In their findings, they succeeded in maximizing the liquid hydrocarbon yield to 94.5% by lowering the methane yield to 2.2%. Tomer and co-workers examined the effect of reaction condition on the hydrogenolysis of waste polypropylene using a nanoshaped (nanocuboid and nanorod) cerium oxide supporting material (Ru/ CeO 2 ) (Table 1, entry 15).…”

Two Mesoporous Domains Are Better Than One for Catalytic Deconstruction of Polyolefins

“…H 2 deficiency on the active surface, originating from insufficient adsorption of H 2 , or a high energy barrier for product desorption, leads to the cleavage pathway of Scheme a. Increasing H 2 pressure or adding a H reservoir can enable hydrocarbon desorption to become kinetically competitive with C–C bond cleavage. , Small Ru particles, or isolated Ru sites, also favor internal bond cleavage, whereas large Ru particles catalyze terminal hydrogenolysis to give methane. Another strategy for reducing gas products involves Pt nanoparticles (NPs) with fewer unsaturated edge and corner sites, or supported on carbon …”

Catalytic conversion of polyethylene into aromatics with Pt/ZSM-5: insights into reaction pathways and rate-controlling step regulation

“…8 Notably, the PE waste generated each year accounts for ∼85% of annually produced PE. 9 Nowadays, the accumulation rates of waste PE are far beyond the industrial processing capacity. Therefore, development of an efficient recycling method to tackle the rapidly accumulated PE is essential both economically and environmentally.…”