This study focuses on the development of innovative microchannel-structured beads, designed to revolutionize diffusional mass transfer inside porous materials. Specifically, we created microchannel-structured alumina beads (AS0, 3 mm in diameter), using a combined phase-inversion and sintering process. This was followed by incorporating varying amounts of mesoporous γ-Al₂O₃ phase through a sol–gel process for the first time to enhance the internal specific surface area (S_BET) of the AS0 beads, along with a 2 wt% cobalt catalytic phase applied via impregnation (2Co/ASx). A second approach for integrating cobalt-γ-Al₂O₃ inside the beads is a one-step co-impregnation process (2Co/ASx (co-imp.), x ranges from 0 to 4 with varying amounts of γ-Al₂O₃ sols). These samples were then subjected to the degradation of sulfamethoxazole (SMX) in the peroxymonosulfate (PMS)-activated AOPs system under mild reaction conditions. Experimental results demonstrated that the microchannel-structured beads with higher S_BET displayed enhanced catalytic activity, with 2Co/ASx (co-imp.) achieving better catalytic efficiency compared to 2Co/ASx. This improvement was attributed to larger exposed open surface pores on the beads, which facilitated diffusional mass transfer of reactants and products. However, overloading γ-Al₂O₃ could reduce the accessibility of surface pores, increase mass transfer resistance at high pollutant concentrations (40 mg/L SMX), and consequently reduce SMX removal efficiency. More importantly, it is unexpected that the catalyst exhibited substantially higher performance after regeneration, achieving 96.32 % SMX removal in 20 min, compared to 95.75 % in 120 min for the fresh catalyst. This was attributed to the enhanced accessibility of open pores on the bead surface during regeneration, highlighting the significance of intensifying the diffusional transfer process to benefit catalytic reactions. Such benefits are highly transferable to a broader spectrum of heterogeneous catalysis applications.

中文翻译：

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用于微尺度工艺强化的创新微通道结构微珠：磺胺甲噁唑减排水处理案例研究


本研究的重点是开发创新的微通道结构微珠，旨在彻底改变多孔材料内部的扩散传质。具体来说，我们使用相反转和烧结相结合的工艺创建了微通道结构的氧化铝珠（AS0，直径 3 mm）。随后，首次通过溶胶-凝胶工艺掺入不同量的介孔 γ-Al₂O₃ 相，以提高 AS0 珠的内部比表面积 （S_BET），以及通过浸渍 （2Co/ASx） 施加的 2 wt% 钴催化相。将钴-γ-Al₂O₃ 整合到珠子内的第二种方法是一步共浸渍工艺（2Co/ASx （co-imp.），x 范围从 0 到 4，具有不同数量的 γ-Al₂O₃ 溶胶）。然后在温和的反应条件下，这些样品在过氧一硫酸盐 （PMS） 活化的 AOPs 系统中对磺胺甲噁唑 （SMX） 进行降解。实验结果表明，具有较高 S_BET 的微通道结构珠子显示出增强的催化活性，与 2Co/ASx 相比，2Co/ASx （co-imp.） 实现了更好的催化效率。这种改进归因于磁珠上更大的暴露开放表面孔，这促进了反应物和产物的扩散传质。然而，γ-Al₂O₃ 过载会降低表面孔隙的可及性，增加高污染物浓度 （40 mg/L SMX） 下的传质阻力，从而降低 SMX 去除效率。 更重要的是，出乎意料的是，催化剂在再生后表现出了更高的性能，在 20 分钟内实现了 96.32% 的 SMX 去除率，而新催化剂在 120 分钟内实现了 95.75% 的去除率。这归因于再生过程中珠子表面开孔的可及性增强，突出了加强扩散转移过程以利于催化反应的重要性。这些优势可以高度转移到更广泛的多相催化应用中。