MgCr2O4 改性 CuO/Cu2O 用于高温热化学储能，具有高氧化还原活性和抗烧结性,ACS Applied Materials & Interfaces

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MgCr2O4 改性 CuO/Cu2O 用于高温热化学储能，具有高氧化还原活性和抗烧结性
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2022-09-19 , DOI: 10.1021/acsami.2c09519
Jiali Deng ₁ , Changdong Gu ₂ , Haoran Xu ₁ , Gang Xiao ₁

Affiliation

金属氧化物作为基于气固反应的高能量密度高温热化学储能系统是聚光太阳能电站未来发展的关键需求。铜基体系具有高焓变和低成本，但其严重的烧结导致反应性差。在这项研究中，MgCr ₂ O ₄被装饰在 CuO/Cu ₂O 面有效提高烧结温度，缓解烧结问题。再氧化度由46%提高到99.9%，反应时间缩短3.7倍。储存和释放的热化学能量密度分别达到-818.23和812.90 kJ/kg。600 次循环后，氧化活性保持在 98.77%。材料表征表明纳米MgCr ₂ O ₄在可逆反应过程中均匀地负载在CuO/Cu ₂ O的表面，金属氧化物与促进剂之间存在强相互作用。密度泛函理论 (DFT) 计算进一步证实了 CuO/Cu ₂ O–MgCr ₂ O ₄结合能大，铜空位形成能增加，能有效抑制烧结。揭示了MgCr ₂ O ₄对CuO/Cu ₂ O的改性机理，可为合理设计具有耐烧结性和氧化还原活性的热化学储能材料提供指导。

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MgCr2O4-Modified CuO/Cu2O for High-Temperature Thermochemical Energy Storage with High Redox Activity and Sintering Resistance

Metal oxides as high-temperature thermochemical energy storage systems with high energy density based on the gas–solid reaction are a critical demand for the future development of concentrated solar power plants. A copper-based system has high enthalpy change and low cost, but its serious sintering leads to poor reactivity. In this study, MgCr₂O₄ is decorated on the CuO/Cu₂O surface to effectively increase the sintering temperature and alleviate the sintering problem. The re-oxidation degree is increased from 46 to 99.9%, and the reaction time is shortened by 3.7 times. The thermochemical energy density of storage and release reach −818.23 and 812.90 kJ/kg, respectively. After 600 cycles, the oxidation activity remains 98.77%. Material characterization elucidates that nanosized MgCr₂O₄ is uniformly loaded on the surface of CuO/Cu₂O during the reversible reaction, and there is a strong interaction between metal oxides and prompter. Density functional theory (DFT) calculation further confirms that CuO/Cu₂O–MgCr₂O₄ has large binding energy and the formation energy of copper vacancy increases, which can effectively inhibit sintering. The modification mechanism of CuO/Cu₂O by MgCr₂O₄ is revealed, which can provide guidance for the reasonable design of thermochemical energy storage materials with sintering resistance and redox activity.

更新日期：2022-09-19

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