3D-printed adsorbents are gaining increased attention owing to their potential in overcoming operational challenges faced by the conventionally structured counterparts. In this work, cylindrical scaffolds of triply periodic minimal surface (TPMS) configuration were synthesized using 3D-printing by stereolithography. This unique gyroid sheet TPMS network was selected as it offers a high surface-area-to-volume ratio. The surface of the scaffolds was modified by a silanization process followed by coating via grafting with zeolite 13X crystals toward CO adsorption application. A secondary zeolite coating step was also employed to enhance the zeolite 13X loading, resulting in zeolite loadings of 16 wt% and 23 wt% after the primary and secondary coatings, respectively. Following morphological and structural characterization, the CO adsorption performance of the 3D-printed materials was evaluated with respect to adsorption capacity, kinetics, selectivity, and heat of adsorption. Cyclic stability was also assessed over CO adsorption–desorption pressure swing adsorption cycles at 25 °C. Comparative analysis showed that the 3D-printed coated samples exhibited higher CO/N selectivity and improved cyclic stability with a slightly lower CO adsorption capacity than the zeolite 13X powder. The heat of adsorption ranged from 18 to 41 kJ mol for both the powder and the coated adsorbents, indicating physisorption. The gyroid lattice of the 3D-printed structures, featuring a densely arranged network of smooth, interconnected flow channels, facilitated molecular transport thus yielding higher CO adsorption kinetics than the powder. Indicatively, the primary and secondary coatings attained an equilibrium capacity of 4 mmol g at 25 °C in 62 and 57 min, respectively, while the powder required 110 min at the same conditions. The 3D-printed materials exhibited also significantly higher CO/N selectivity values of 569 and 115 at 50 mbar and 1 bar, respectively, for the primary coating sample, and 536 and 73 at 50 mbar and 1 bar, respectively, for the secondary coating one. The findings highlight the potential of 3D-printing to produce coated structured adsorbents with complex geometries for sustainable CO capture and gas adsorption processes.

中文翻译：

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用于二氧化碳吸附的沸石涂层 3D 打印陀螺仪支架

3D 打印吸附剂因其在克服传统结构吸附剂所面临的操作挑战方面的潜力而受到越来越多的关注。在这项工作中，使用立体光刻技术的 3D 打印合成了三周期最小表面 (TPMS) 配置的圆柱形支架。选择这种独特的陀螺仪片 TPMS 网络是因为它具有高表面积与体积比。通过硅烷化工艺对支架表面进行改性，然后通过接枝 13X 沸石晶体进行涂层，以用于 CO 吸附应用。还采用二次沸石涂覆步骤来增强沸石 13X 负载量，在初次和二次涂覆后分别产生 16 wt% 和 23 wt% 的沸石负载量。在进行形态和结构表征后，从吸附容量、动力学、选择性和吸附热方面评估了 3D 打印材料的 CO 吸附性能。还评估了 25 °C 下 CO 吸附-解吸变压吸附循环的循环稳定性。对比分析表明，与沸石13X粉末相比，3D打印的涂层样品表现出更高的CO/N选择性和改善的循环稳定性，且CO吸附容量略低。粉末和涂层吸附剂的吸附热范围为 18 至 41 kJ mol，表明物理吸附。 3D 打印结构的螺旋晶格具有密集排列的平滑、互连的流动通道网络，促进了分子传输，从而产生比粉末更高的 CO 吸附动力学。表明，在 25 °C 下，初级和次级涂层分别在 62 和 57 分钟内达到 4 mmol g 的平衡容量，而粉末在相同条件下需要 110 分钟。 3D 打印材料还表现出显着更高的 CO/N 选择性值，对于初级涂层样品，在 50 mbar 和 1 bar 下分别为 569 和 115，对于二次涂层样品，在 50 mbar 和 1 bar 下分别为 536 和 73一。研究结果强调了 3D 打印生产具有复杂几何形状的涂层结构化吸附剂的潜力，用于可持续的二氧化碳捕获和气体吸附过程。