Designing complex hollow nano-/microspheres with multilayered structures of two or more metal oxides seems to be interesting to answer the request for novel catalytic structures. Herein, we develop a copper-alumina spinel hollow sphere with a triple-shell structure applied as a novel catalyst for the cycloaddition of CO₂ at atmospheric pressure. Different operating conditions such as reaction temperature, various solvents and reaction time were studied in this reaction. Besides, different epoxides were converted at 80°C, under bubbling of CO₂ at atmospheric pressure, a catalyst loading of 3 wt.% and a reaction time of 24 h with isolated yields up to 100% of the carbonate. In addition, the kinetics of the reaction was investigated at different reaction temperatures by calculating the reaction rate constant and activation energy (based on the Arrhenius equation). The nanoporous triple-shell CuAl₂O₄ hollow microspheres reduce the mass transfer path of different reactant and product molecules along with better accessibility of interior active sites that improves the catalytic efficiency with suitable activity and remarkable cycling stability.

设计具有两种或多种金属氧化物多层结构的复杂空心纳米/微球似乎很有趣，可以满足对新型催化结构的需求。在本文中，我们开发了具有三壳结构的铜铝尖晶石空心球，将其用作在大气压下环化CO ₂的新型催化剂。在该反应中研究了不同的操作条件，例如反应温度，各种溶剂和反应时间。此外，不同的环氧化物在80℃，在大气压下鼓泡CO ₂，催化剂负载量为3重量％，反应时间为24小时，分离的产率为碳酸盐的100％。此外，通过计算反应速率常数和活化能（基于Arrhenius方程），研究了在不同反应温度下的反应动力学。纳米多孔三壳CuAl ₂ O ₄空心微球减少了不同反应物和产物分子的传质路径，并改善了内部活性位的可及性，从而以合适的活性和出色的循环稳定性提高了催化效率。