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Efforts to selectively convert polypropylene (≈30 % of all plastic waste) have not been particularly successful. Typical distributions span from gas to solid products, highlighting a challenging cleavage control. Here, carbon‐supported platinum nanoparticles were designed for complete hydrocracking into liquid hydrocarbons (C5–C45). The metal and carrier phases operated synergistically. The cleavage activity depended on platinum and its rate rose with decreasing particle size. The carbon carrier controlled selectivity via hydrocarbon binding strength, which depended on the chain length and on the surface oxygen concentration. An optimal binding provided by carbons with high oxygen content promoted both adsorption of long chains and desorption of short products. This strategy achieved an unprecedented 80 % selectivity toward motor oil (C21–C45). Carbons exhibiting too strong binding (low oxygen content) hindered product desorption, while non‐binding materials (e. g., silica or alumina) did not promote plastic–Pt contact, leading in both cases to low performance. This work pioneers design guidelines in a key process towards a sustainable plastic economy. [ABSTRACT FROM AUTHOR]

The impact of carbon monoxide on CO2‐to‐methanol catalysts has been scarcely investigated, although CO will comprise up to half of the carbon feedstock, depending on the origin of CO2 and process configuration. In this study, copper‐based systems and ZnO−ZrO2 are assessed in cycling experiments with hybrid CO2−CO feeds and their CO sensitivity is compared to In2O3‐based materials. All catalysts are found to be promoted upon CO addition. Copper‐based systems are intrinsically more active in CO hydrogenation and profit from exploiting this carbon source for methanol production, whereas CO induces surplus formation of oxygen vacancies (i. e. the catalytic sites) on ZnO−ZrO2, as in In2O3‐based systems. Mild‐to‐moderate deactivation occurs upon re‐exposure to CO2‐rich streams, owing to water‐induced sintering for all catalysts except ZnO−ZrO2, which responds reversibly to feed variations, likely owing to its more hydrophobic nature and the atomic mixing of its metal components. Catalytic systems are categorized for operation in hybrid CO2−CO feeds, emphasizing the significance of catalyst and process design to foster advances in CO2 utilization technologies. [ABSTRACT FROM AUTHOR]

Carbon-supported Pt catalysts enable this outcome, for which activity and selectivity are tunable via Pt particle size and surface oxygen content of carbon, respectively. Cover Feature: Direct Conversion of Polypropylene into Liquid Hydrocarbons on Carbon-Supported Platinum Catalysts (ChemSusChem 23/2021) Keywords: cracking; heterogeneous catalysis; plastic waste; polypropylene; recycling EN cracking heterogeneous catalysis plastic waste polypropylene recycling 5076 5076 1 12/08/21 20211206 NES 211206 B The Cover Feature b shows a landscape reflecting the pressing problem of plastic waste generation where a resolute humanoid emerges, symbolizing the potential of chemical recycling. [Extracted from the article]