Efficient\nHydrogenolysis of Consumer-Grade High-Density\nPolyethylene Wastes over MgAl-Layered Double Oxide-Supported Ru Catalysts

Hydrogenolysis of consumer-grade\nhigh-density polyethylene (HDPE)\nis a pivotal strategy for upcycling plastic waste into value-added\nfuels. Though Ru catalysts demonstrated activity in the hydrogenolysis\nof inert C–C bonds of HDPE, the precise design of Ru nanoparticles\nstill represents a critical challenge to boost the performance. Here,\nultrafine Ru nanoparticles (∼1 nm) supported on MgAl-layered\ndouble oxides (MgAl-LDO) exhibited a selectivity over 90% for liquid\nfuels, lubricants, and waxes in the hydrogenolysis of HDPE. By tuning\nthe thermal treatments and Mg/Al ratios, the Ru<sup>δ+</sup>/Ru<sup>0</sup> ratio and acidity/basicity of MgAl-LDO were determined\nas critical performance descriptors. Notably, the confining effects\nof the layered structure of MgAl-LDO can be optimized to facilitate\nthe effective dispersion of Ru nanoparticles, even at elevated loadings\nof up to 9%. Moreover, the Ru/Mg<sub>1</sub>Al-LDO catalyst exhibited\ngood applicability in the hydrogenolysis of various HDPE substrates\nand excellent stability, maintaining the structure and activity in\nfive recycling runs.