Structure–performance relationships in heterogeneous catalysts for polyolefin plastic hydroconversion

The persistent accumulation of plastic waste poses severe environmental and economic challenges, and current management routes remain unsustainable. In recent years, catalytic hydroconversion has emerged as an attractive route to upcycle polyolefin plastics into fuels, lubricants, and value-added chemicals under comparatively mild conditions. Progress is, however, constrained by an incomplete mechanistic understanding of structure–performance relationships for these hydroconversion catalysts. This review summarizes recent advances in polyolefin hydrogenolysis and hydrocracking within a unified descriptor framework. We systematically examine key parameters, including metal particle size and electronic environment; the nature and architecture of the support material; metal–acid balance, proximity, and synergistic interactions; and polymer-specific effects such as adsorption entropy penalties, diffusion limitations, and processive conversion behaviour. Consolidating these insights, we propose practical design principles to guide the development of efficient, selective and stable catalysts for sustainable plastic upcycling. • Recent advances in heterogeneous catalytic hydroconversion of polyolefin plastics are critically reviewed. • Structure–performance relationships are elucidated using key mechanistic and materials-based descriptors. • Emerging perspectives and future research directions for sustainable plastic upcycling are identified.