Efficient Homolytic Cleavage of H2O2 on Hydroxyl‐Enriched Spinel CuFe2O4 with Dual Lewis Acid Sites

• Published in: Angewandte Chemie International Edition Vol. 63; no. 17; pp. e202401434 - n/a
• Main Authors: Tian, Lei, Tang, Zi‐Jun, Hao, Le‐Yang, Dai, Ting, Zou, Jian‐Ping, Liu, Zhao‐Qing
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 22-04-2024
• Edition: International ed. in English
• Subjects: Acidity; Bonding strength; Catalysts; Cleavage; Continuous flow; Copper ferrite; Electron transfer; Enrichment; Flow stability; Free energy; H2O2; homolytic cleavage; Hydrogen peroxide; hydroxyl radical; hydroxyl-enriched CuFe2O4; Lewis acid; Spinel
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202401434

Traditional H2O2 cleavage mediated by macroscopic electron transfer (MET) not only has low utilization of H2O2, but also sacrifices the stability of catalysts. We present a non‐redox hydroxyl‐enriched spinel (CuFe2O4) catalyst with dual Lewis acid sites to realize the homolytic cleavage of H2O2. The results of systematic experiments, in situ characterizations, and theoretical calculations confirm that tetrahedral Cu sites with optimal Lewis acidity and strong electron delocalization can synergistically elongate the O−O bonds (1.47 Å → 1.87 Å) in collaboration with adjacent bridging hydroxyl (another Lewis acid site). As a result, the free energy of H2O2 homolytic cleavage is decreased (1.28 eV → 0.98 eV). H2O2 can be efficiently split into ⋅OH induced by hydroxyl‐enriched CuFe2O4 without MET, which greatly improves the catalyst stability and the H2O2 utilization (65.2 %, nearly 2 times than traditional catalysts). The system assembled with hydroxyl‐enriched CuFe2O4 and H2O2 affords exceptional performance for organic pollutant elimination. The scale‐up experiment using a continuous flow reactor realizes long‐term stability (up to 600 mL), confirming the tremendous potential of hydroxyl‐enriched CuFe2O4 for practical applications.
Macroscopic electron transfer (MET) is indispensable during the traditional H2O2 cleavage process. We demonstrate a non‐redox hydroxyl‐enriched spinel CuFe2O4 with dual Lewis acid sites to realize the homolytic cleavage of H2O2 without MET, which truly promotes H2O2 utilization and the catalyst stability, thereby expanding the applicability of heterogeneous catalysts in environmental remediation and organic synthesis.