钡含量对（La_0.5Sr_0.5）_1-xBa_xFe_0.6Co_0.4O₃ 化学链甲烷干重整性能的影响

Chemical looping dry reforming of methane (CL-DRM) has the potential as an efficient technology to achieve carbon neutrality in terms of converting CH₄ and CO₂ to various value-added products with the minimal separation requirements. Currently, a major challenge facing this technology is the design and development of oxygen carriers with good reactivity and stability. Herein, the Ba-substituted (La_0.5Sr_0.5)_1-xBa_xFe_0.6Co_0.4O₃ perovskite oxides with the anchored nanoparticles as the novel oxygen carriers were synthesized and investigated for the redox performance in the CL-DRM process based on various characterization technologies. It is found that La_0.35Sr_0.35Ba_0.3Fe_0.6Co_0.4O₃ oxygen carrier (x=0.3) increases the amount of oxygen consumed (5.29 mmol·g^-1) and shows a higher oxygen diffusion rate to achieve the CH₄ conversion of 84.3% and syngas yield of 15.23 mmol·g^-1 in the CH₄ reduction step. Meanwhile, the syngas selectivity of 95.8%, the CO selectivity of 70.0% and carbon deposition of 1.36 mmol·g^-1 can be obtained. Analysis of the gas generation rate during methane reduction shows that Ba substitution can optimize the lattice structure of the oxygen carrier, leading to high ion mobility, promoting rapid diffusion of oxygen in the bulk phase, and thus improving CH₄ conversion. Furthermore, the excellent oxygen carrier also exhibits the high structure stability and the stable regeneration ability by CO₂ during the successive redox cycles.