The sorption enhanced chemical looping reforming is a prospective technology for high-quality hydrogen production. In this technology, the full benefits of catalysis, oxygen transfer, and CO₂ adsorption are achieved by the utilization of oxygen carriers and sorbents. However, most sorbents that are mixed physically into the reforming bed are liable to encountering ash fouling and porosity reduction, preventing CO₂ adsorption and sorbent regeneration. In this work, we develop a multifunctional composite oxygen carrier, which combines the NiO/NiAl₂O₄ catalyst with the CaO sorbent into a one-body composite pellet. Compared with the conventional physically mixed oxygen carrier, the composite oxygen carrier shows uniform element distribution, superior reducibility, and shortened dead time, resulting in enhanced CO₂ adsorption capacity, high H₂ production efficiency, and excellent ethanol conversion. Furthermore, during 20 cycle tests, the stable CO₂ adsorption capacity and H₂ concentration of composite oxygen carrier were maintained, while the H₂ concentration of mixed oxygen carrier sharply decreased because of deteriorated adsorption performance. The results confirm that the multifunctional composite oxygen carrier is more suitable than the mixed oxygen carrier for CO₂ adsorption and high purity hydrogen production. This work opens a new avenue toward the performance improvement of oxygen carriers.

吸附增强的化学循环重整是高质量制氢的前瞻性技术。在该技术中，通过利用氧载体和吸附剂，实现了催化、氧转移和 CO ₂吸附的全部优势。然而，大多数物理混合到重整床中的吸附剂容易遇到灰垢和孔隙率降低，从而阻止 CO ₂吸附和吸附剂再生。在这项工作中，我们开发了一种多功能复合氧载体，它结合了 NiO/NiAl ₂ O ₄催化剂与 CaO 吸附剂形成一体式复合颗粒。与传统的物理混合氧载体相比，复合氧载体元素分布均匀，还原性好，死时间缩短，CO ₂吸附能力增强，H ₂生产效率高，乙醇转化率高。此外，在20次循环试验中，复合氧载体的CO ₂吸附容量和H ₂浓度保持稳定，而H ₂由于吸附性能变差，混合氧载体的浓度急剧下降。结果证实多功能复合氧载体比混合氧载体更适合于CO ₂吸附和高纯度制氢。这项工作为氧载体的性能改进开辟了一条新途径。