Catalytic conversion of waste polyolefins to value-added alkylaromatics could contribute to carbon recycling. Compared with tandem hydrogenolysis/aromatization of polyethylene (PE) catalyzed by Pt/γ-Al₂O₃ at 280°C, both a 5-fold enhancement in the rate of C–C bond scission and a doubling of the molar yield of alkylaromatics were achieved using a more acidic Pt/F-Al₂O₃ catalyst instead. Bifunctional (metal/acid) catalysts also generate alkylaromatic products with lower average carbon numbers (ca. C₂₀), similar to conventional anionic surfactants. Because physical mixtures of weakly acidic Pt/γ-Al₂O₃ or non-acidic Pt/SiO₂ with strongly Brønsted acidic Cl-Al₂O₃ or F-Al₂O₃ are also effective, the tandem reaction does not require nanoscale intimacy between metal and acid active sites. Kinetic studies using triacontane (norm-C₃₀H₆₂) as a model for PE show that the Pt-catalyzed dehydrogenation/hydrogenation reactions are quasi-equilibrated, while the acid-catalyzed C–C bond scission and skeletal transformations (isomerization and cyclization) determine the overall rates of depolymerization and aromatic formation.

将废弃聚烯烃催化转化为增值烷基芳烃可能有助于碳回收。_{与Pt/γ-Al 2} O ₃在280℃催化聚乙烯（PE）串联氢解/芳构化相比，C-C键断裂速率提高了5倍，烷基芳烃摩尔产率提高了一倍使用酸性更强的 Pt/F-Al ₂ O ₃催化剂代替来实现。双功能（金属/酸）催化剂还可生成平均碳数较低（约 C ₂₀ ）的烷基芳族产物，与传统阴离子表面活性剂类似。因为弱酸性Pt/γ-Al ₂ O ₃或非酸性Pt/SiO _{2的物理混合物}具有强布朗斯台德酸性的Cl-Al ₂ O ₃或F-Al ₂ O ₃也有效，串联反应不需要金属和酸活性位点之间的纳米级紧密接触。使用三十烷（ norm -C ₃₀ H ₆₂ ）作为 PE 模型的动力学研究表明，Pt 催化的脱氢/氢化反应是准平衡的，而酸催化的 C-C 键断裂和骨架转化（异构化和环化）确定解聚和芳香族形成的总体速率。