High-entropy perovskite oxide washcoated porous alumina ceramic as a superb catalyst for activating peroxymonosulfate to eliminate refractory organic pollutants

Utilizing cobalt-containing oxides as catalysts is one of the most popular ways of activating peroxymonosulfate (PMS) to generate sulfate radical (SO4−) for elimination of organic pollutants. However, it still remains a great challenge to realize high activity, good stability, and easy recyclability at the same time. Herein, we demonstrate that high-entropy perovskite oxide (HEPO) washcoated porous alumina ceramic (La(Co0.2Al0.2Fe0.2Mn0.2Cu0.2)O3@PAC) is a superb catalyst for PMS activation. In particular, benefiting from unique multimetallic composition and entropy-stabilized structure, the La(Co0.2Al0.2Fe0.2Mn0.2Cu0.2)O3@PAC manifested high catalytic activity with a turnover frequency (TOF) up to 15.38 min−1 in activating PMS for degradation of antibiotic pollutant metronidazole (MNZ). Meanwhile, the high stability of HEPO gave rise to a significant decrease of cobalt leaching (0.111 mg L−1) in comparison with LaCoO3@PAC catalyst (1.71 mg L−1). Moreover, monolithic porous architecture of La(Co0.2Al0.2Fe0.2Mn0.2Cu0.2)O3@PAC could not only endow this catalyst with easy recyclability but ensure high permeability for rapid mass transfer of guest species. Our work exemplifies the superiority of HEPO-based monolithic catalyst as a new promising activator of PMS for water remediation.