The sintering of oxygen carrier materials can be circumvented by operating chemical looping at relatively low temperatures (<750 ^oC). However, low temperature has a degrading effect on the redox kinetics of the materials and thereby limited efficiencies. In the current work, we report several Co, Cu co-doped spinel-structured ferrites as effective redox materials in the chemical looping scheme for CO₂ thermo splitting at 650 ^oC. Cu_0.2Co_0.8Fe₂O₄ presents high average CO₂ splitting rate of ∼144.9 μmol.g^-1.min^-1 and CO yield of ∼9.0 mmol. g^-1 with satisfactory stability over cyclic redox operations. The improved performance can be attributed to the improved reduction of iron oxides by Cu, Co co-dopant, and the reversible phase change of the reduced sample in the CO₂ splitting stage. Additionally, increasing Cu doping amount leads to the formation of insufficiently active impurities which is unfavorable for the CO₂ thermo-splitting. The synergy in this work can be helpful for the design of the redox materials at moderate temperatures.

氧气载体材料的烧结可通过在相对较低的温度（<750 ^o C）下进行化学循环来避免。然而，低温对材料的氧化还原动力学具有降解作用，从而限制了效率。在当前的工作中，我们报告了几种Co，Cu共掺杂的尖晶石结构的铁氧体，它们是在650 ^o C下进行CO ₂热裂解的化学循环方案中的有效氧化还原材料。Cu _0.2 Co _0.8 Fe ₂ O ₄具有较高的平均CO ₂分离速率约为144.9μmol.g ^-1 .min ^-1，CO产率约为9.0 mmol。g ^-1在循环氧化还原操作方面具有令人满意的稳定性。性能的提高可归因于Cu，Co共掺杂剂对氧化铁的还原作用增强，以及还原的样品在CO ₂裂解阶段可逆的相变。另外，增加的Cu掺杂量导致活性不足的杂质的形成，这对于CO ₂热分解是不利的。这项工作的协同作用有助于在中等温度下设计氧化还原材料。