五元铁基氧载体深度释氧能力及废塑料化学链制氢研究OA

As the core clean carrier of energy transformation,the hydrogen production is still limited by the high energy consumption and high carbon emission of traditional processes.The chemical looping hydrogen production technology based on the principle of chemical looping combustion achieves efficient hydrogen production and in-situ separation of products through lattice oxygen transfer of oxygen carriers,in which the performance of oxygen carriers is the key bottleneck of industrialization.In this study,five groups of A-site single metal modified spinel ferrites(AFe2O4,A=Cu,Ni,Mn,Sr,Ca)and five-element oxygen carriers(Cu0.2 Ca0.2 Ni0.2 Mn0.2 Sr0.2 Fe2O4)were designed and prepared by high-temperature solid-state-ball milling method.The characterization of X-ray diffraction(XRD)and H2 temperature-programmed reduction(H2-TPR)confirmed that the five-membered system composite oxygen carrier significantly balanced the lattice oxygen activity and structural stability through the"dilution effect"of multiple metals.The fixed bed experiment using polypropylene waste plastic as fuel shows that when the oxygen carrier supply coefficient is 0.5,the purity of hydrogen production catalyzed by the five-element oxygen carrier reaches 93.03%,which is 32.4%-45.8%higher than that of the binary system.After reduction,the main phase structure of spinel is still maintained in the five-membered system,while the pure Fe2O3 is transformed into Fe3O4 due to phase transition sintering,which leads to cycle failure.This study shows that the synergistic effect of multi-metals can break through the"activity-stability"trade-off problem of oxygen carriers and provide a high-performance material solution for hydrogen production from waste plastics.