Polyolefins represent the most extensively manufactured category of plastics globally, whose ultra strong chemical stability makes their recycling challenging. Hydrogenolysis has emerged as a promising chemical recycling strategy for polyolefins, in which supports play an important but “silent” role. This review focuses on recent advances in polyolefin hydrogenolysis, with particular emphasis on how supports (acidity/basicity, reducibility, size/pore, optical activity) architecture dictate efficiency in the process. It also summarizes characterization methodologies for elucidating support effects. This review bridges the current research void in support-effect-mediated regulation of polyolefin hydrogenolysis, establishing rational design principles for carriers to boost the performance of metal-supported catalysts.

A green and scalable strategy has been developed for the synthesis of lignin-derived Zn single atom/N-codoped porous carbon (LCN@Zn-SAC) containing similar ZnN_x sites with carbonic anhydrases. This catalyst exhibits superior activity on the α-alkylation of ketones with alcohols via borrowing hydrogen strategy (TON up to 15 h⁻¹) than most of previously reported works. The dehydrogenation of benzyl alcohol is the rate-determining step based on kinetic experiment results. According to experimental and theoretical calculation results, Zn electron density is inversely proportional to reaction energy barriers, because Zn sites with less positive charge (ZnN₄ and ZnN₃C) in Zn-SACs display better borrowing hydrogen ability than other Zn sites. Furthermore, this catalyst can be recycled by simple centrifugation, which can be reused at least 8 runs with no obvious lose in activity. To the best of our knowledge, this is the first example of non-noble metal-SAC-catalyzed α-alkylation via borrowing hydrogen strategy.