Thermally Driven Hydrogenation of CO2 to Light Olefins Over Hollow Cubic In2O3-La-ZIF-8 Tandem Catalyst

en Thermally driven hydrogenation of CO 2 to light olefins (C 2 = –C 4 = ) using metal oxide-zeolite tandem catalysts is an effective strategy for achieving carbon neutrality. However, progress in this area is constrained by zeolite pore transport limitations, acid-site inactivation, and surface carbon poisoning. To address these issues, we replaced conventional zeolites with La-modified ZIF-8 and combined it with hollow cubic In 2 O 3 to develop a novel In 2 O 3 -La-ZIF-8 tandem catalyst. Our study investigates the effects of the hydrothermal reaction temperature used for synthesizing In 2 O 3 and the La content in ZIF-8 on catalytic performance. We also found that the oxygen vacancy (O V ) concentration in In 2 O 3 can be substantially regulated by adjusting the hydrothermal temperature. The In 2 O 3 sample with the highest O V concentration not only promotes the formation of reaction intermediates but also markedly reduces the energy barrier of the rate-determining step in methanol synthesis. Comprehensive characterization and simulation analyses indicate that La incorporation enhances the thermal stability of ZIF-8, improves its ability to adsorb and activate reaction intermediates, and effectively adjusts its acid-base properties. Under a reaction pressure of 3.0 MPa and a temperature of 360°C, the hollow cubic In 2 O 3 -La-ZIF-8 tandem catalyst achieves 23.5% CO 2 conversion with 65.3% C 2 = –C 4 = selectivity. 摘要 zh 利用金属氧化物-分子筛串联催化剂 , 通过热驱动将CO 2 转化为低碳烯烃(C 2 = –C 4 = ) , 是实现碳中和的有效策略。然而 , 该领域的发展受到分子筛孔道传质限制、酸性位点失活及表面积碳等问题的制约。为解决这些难题 , 本研究以La修饰的ZIF-8替代传统分子筛 , 并将其与空心立方体In 2 O 3 相结合 , 开发了一种新型的In 2 O 3 -La-ZIF-8串联催化剂。系统探究了In 2 O 3 水热合成温度以及ZIF-8中La含量对催化剂性能的影响。通过调节水热温度可显著调控In 2 O 3 中的氧空位浓度 , 具有最高氧空位浓度的In 2 O 3 样品不仅能促进反应中间体的生成 , 还可显著降低甲醇合成过程中决速步骤的能垒。综合表征与模拟分析表明 , La的引入增强了ZIF-8的热稳定性 , 提升了其对反应中间体的吸附与活化能力 , 并有效调节了其酸碱性质。在3.0 MPa、360°C的反应条件下 , 空心立方In 2 O 3 -La-ZIF-8串联催化剂上实现了23.5%的CO 2 转化率与65.3%的低碳烯烃选择性。