Chinese Academy of Sciences Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR 999077, China.
Proc Natl Acad Sci U S A. 2023 Apr 11;120(15):e2220608120. doi: 10.1073/pnas.2220608120. Epub 2023 Apr 5.
A precise modulation of heterogeneous catalysts in structural and surface properties promises the development of more sustainable advanced oxidation water purification technologies. However, while catalysts with superior decontamination activity and selectivity are already achievable, maintaining a long-term service life of such materials remains challenging. Here, we propose a crystallinity engineering strategy to break the activity-stability tradeoff of metal oxides in Fenton-like catalysis. The amorphous/crystalline cobalt-manganese spinel oxide (A/C-CoMnO) provided highly active, hydroxyl group-rich surface, with moderate peroxymonosulfate (PMS)-binding affinity and charge transfer energy and strong pollutant adsorption, to trigger concerted radical and nonradical reactions for efficient pollutant mineralization, thereby alleviating the catalyst passivation by oxidation intermediate accumulation. Meanwhile, the surface-confined reactions, benefited from the enhanced adsorption of pollutants at A/C interface, rendered the A/C-CoMnO/PMS system ultrahigh PMS utilization efficiency (82.2%) and unprecedented decontamination activity (rate constant of 1.48 min) surpassing almost all the state-of-the-art heterogeneous Fenton-like catalysts. The superior cyclic stability and environmental robustness of the system for real water treatment was also demonstrated. Our work unveils a critical role of material crystallinity in modulating the Fenton-like catalytic activity and pathways of metal oxides, which fundamentally improves our understanding of the structure-activity-selectivity relationships of heterogeneous catalysts and may inspire material design for more sustainable water purification application and beyond.
精确调控异相催化剂的结构和表面性质有望开发出更可持续的高级氧化水净化技术。然而，尽管已经可以获得具有优越去污活性和选择性的催化剂，但保持这些材料的长期使用寿命仍然具有挑战性。在这里，我们提出了一种晶型工程策略，以打破类芬顿催化中金属氧化物的活性-稳定性权衡。非晶/晶态钴锰尖晶石氧化物（A/C-CoMnO）提供了高活性、富含羟基的表面，具有适度的过一硫酸盐（PMS）结合亲和力和电荷转移能量以及较强的污染物吸附能力，从而引发协同的自由基和非自由基反应，实现高效的污染物矿化，从而缓解氧化中间产物积累导致的催化剂钝化。同时，表面受限反应得益于污染物在 A/C 界面的增强吸附，使 A/C-CoMnO/PMS 体系具有超高的 PMS 利用率（82.2%）和前所未有的去污活性（速率常数为 1.48 min），超过了几乎所有现有的异相类芬顿催化剂。该体系在实际水处理中的优越循环稳定性和环境稳健性也得到了证明。我们的工作揭示了材料结晶度在调节类芬顿催化金属氧化物的催化活性和途径方面的关键作用，从根本上提高了我们对异相催化剂结构-活性-选择性关系的理解，并可能激发用于更可持续水净化应用及其他领域的材料设计。
