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Metastable LaOClx Phase Stabilization as an Effective Strategy for Controllable Chlorination of Ethane into 1,2-Dichloroethane

Year: 2025

Type: article

Abstract: LaOCl-mediated ethane chlorination into 1,2-dichloroethane offers a promising pathway for low-temperature, large-scale ethane upgrading. However, under Cl2-rich conditions, LaOCl undergoes detrimental chlorination into lanthanum chloride (LaCl3), accompanied by extensive surface hydroxylation. Such severe structural evolution limits the practical application of La-based catalysts under industrially relevant conditions. In this study, an alumina-stabilized La catalyst was prepared via a coprecipitation method. We demonstrated that strong La-O-Al interactions effectively resist structural degradation of La species under reaction conditions, enabling the modified catalyst to maintain exceptional stability under high Cl2 concentrations. At a C2H6/Cl2 ratio of 4:9, the optimized catalyst achieves an ethane conversion of 61%, with 1,2-dichloroethane selectivity sustained above 74% for 12 h without noticeable deactivation. In contrast, the bulk LaOCl counterpart suffers from rapid over-chlorination, shifting product dominance to trichloroethane within 10 h. Advanced spectroscopy characterization reveals that selectivity loss in LaOCl originates from phase collapse into LaCl3, whereas Al2O3 stabilization preserves the metastable LaOClx phase in a highly dispersed state, ensuring selective C–Cl bond formation. These results highlight the critical role of stabilizing metastable oxychloride phases through robust metal oxide interactions, establishing a design framework for rare-earth catalysts in high-concentration chlorine environments.

Source: Molecules

DOI: 10.3390/molecules30081746

Authors: Yuting Li, Zihan Zhu, Xia Wu, Lei Ma, Xiaohui Sun, Qinggang Liu