Zhewen Ma,Subrata Panda,Qiuyu Zhang,Fengzhan Sun,Darvaish Khan,Wenjiang Ding,Jianxin Zou
For the first time, structure-modified CoS-nanoboxes (CoS-NBs) scaffold as a multifunctional Supporting material has been developed by using a template-consumption method for nanoconfinement of MgH 2 particles within its mesoporous structure (denoted as MgH 2 @CoS-NBs). Microstructural observations via transmission electron microscopy (TEM) reveal the uniform distribution of MgH 2 nanocrystals within the mesoporous networks of CoS-NBs scaffold and the surface decoration of MgH 2 crystals by in-situ formed MgS phase. The peculiar core-shell structured morphology of MgH 2 nanocrystals and the “nano-size effect” notably enhances the thermodynamic properties of MgH 2 through the reduction in hydriding and dehydriding enthalpies (−65.6 ± 1.1 and 68.1 ± 1.4 kJ mol −1 H 2 , respectively). Moreover, the improved hydrogen sorption kinetics can be attributed to the catalytic effect of MgS through reducing the intrinsic kinetic energy barriers for both hydriding and dehydriding (57.4 ± 2.2 and 120.8 ± 3.2 kJ mol −1 H 2 , respectively). The “nano-size effect” of nanoconfined Mg/MgH 2 crystals, the catalyzing effect of MgS and the multifunctional role of CoS-NBs scaffold are likely to be synergistically contributed to the superior hydrogen sorption performances of MgH 2 @CoS-NBs composite, as compared to the pure MgH 2 .
Hydrodeoxygenation of waste polyethylene terephthalate (PET) presents a promising avenue for aromatic production; however, achieving complete deoxygenation alongside high aromatic relative peak area abundance remains a significant challenge. Herein, we demonstrate a novel one-pot coupled pyrolysis process for waste PET and LDPE using a Mesoporous Granular Stacked Zeolite Catalyst (MGS), achieving a greater than 99% aromatic relative peak area abundance in product oil. Comprehensive experiments and characterization reveal that this outstanding catalytic performance stems from the MGS catalyst's exceptionally large specific surface area, abundant mesoporosity, and superior hydrogen transfer capability. Mechanistic investigations employing Density Functional Theory (DFT) elucidate the hydrogen transfer pathway: under the influence of oxygen and aluminium sites within the MGS framework, LDPE undergoes dehydrogenation and cyclization, while activated hydrogen species drive the catalytic pyrolysis of PET. Remarkably, the catalyst exhibits exceptional stability over multiple recycling cycles. This work establishes a promising and sustainable strategy for the chemical recycling of PET and LDPE and provides fundamental mechanistic insights for designing advanced catalysts for hydrogen transfer reactions.
危险品化学品经营许可证（带存储）