Selective Hydrogenolysis Conversion of Polyethylene into Alkyl Oil over Iridium-based Catalyst.

Plastic not only brings convenience but also places a great burden on the environment. Utilizing plastic as low-cost feed-stock for producing valuable chemicals and fuels is one of the most attractive directions. Among the huge types of plastics, polyolefins (PO), especially polyethylene (PE), were the most abundant type and the most difficult to upgrade. Hydrocracking and hydrogenolysis operate at relatively low reaction temperatures which show promising applications. Herein, Iridium-based catalysts were developed and proved to be effective in PE hydrogenolysis under relatively mild conditions. A highest 92.7% percent of liquid products could be obtained under 250°C, 3 MPa of H2 in 8 hours with Ir/γ-Al2O3 catalyst. The Ir catalysts showed better selectivity for liquid products than Ru under similar conversions. The support could also affect the performance, including Lewis acid amount, surface areas, and morphology.

Metal-Free Activation of Molecular Oxygen by 9-Fluorenone-Based Porous Organic Polymers for Selective Aerobic Oxidation.

Oxygen activation is a critical step in heterogeneous oxidative processes, particularly in catalytic, electrolytic, and pharmaceutical applications. Among the various catalysts available for photocatalytic O2 activation, homogeneous aryl ketones are at the forefront. To avoid the degradation and deactivation of aryl ketones, 9-fluorenone-based porous organic polymers were designed and regulated by doping them with co-monomers. The obtained heterogeneous photocatalyst showed good performance in O2 activation, and its performance was better than that of homogeneous 9-fluorenone. The obtained heterogeneous photocatalyst showed good reusability. We believe that the presented method and findings represent an important step toward designing catalysts tailored for specific tasks.

Hydrogenation of levulinic acid to γ-valerolactone over hydrophobic Ru@HCP catalysts.

This study introduces an efficient strategy for promoting the synthesis of γ-valerolactone (GVL) via levulinic acid (LA) hydrogenation. A series of hyper-crosslinked porous polymer (HCP) supported Ru catalysts with different monomers were prepared. The wettabilities were controlled by the surface functional groups. The hydrophobic catalysts showed much higher activity than the hydrophilic ones in the hydrogenation of LA to GVL, highly possible due to the substrate enrichment. Further insight showed that the reaction proceeded through the 4-HVA route. These results illustrated the importance of surface wettability in bio-based molecule upgrading, which is beneficial for catalyst design.