Ni-Induced C-Al 2 O 3 -Framework ( Ni CAF) Supported Core–Multishell Catalysts for Efficient Catalytic Ozonation: A Structure-to-Performance Study

During catalytic ozonation, Al 2 O 3 -supported catalysts usually have stable structures but relatively low surface activity, while carbon-supported catalysts are opposite. To encourage their synergisms, we designed a Ni-induced C-Al 2 O 3 -framework ( Ni CAF) and reinforced it with a Cu–Co bimetal to create an efficient catalyst (CuCo/ Ni CAF) with a core–multishell structure. The partial graphitization of carbon adjacent to Ni crystals formed a strong out-shell on the catalyst surface. The rate constant for total organic carbon removal of CuCo/ Ni CAF (0.172 ± 0.018 min –1 ) was 67% and 310% higher than that of Al 2 O 3 -supported catalysts and Al 2 O 3 alone, respectively. The metals on CuCo/ Ni CAF contributed to surface-mediated reactions during catalytic ozonation, while the embedded carbon enhanced reactions within the solid–liquid boundary layer and in the bulk solution. Moreover, carbon embedment provided a 76% increase in ·OH-production efficiency and an 86% increase in organic-adsorption capacity compared to Al 2 O 3 -supported catalysts. During the long-term treatment of coal-gasification wastewater (∼5 m 3 day –1 ), the pilot-scale demonstration of CuCo/ Ni CAF-catalyzed ozonation revealed a 120% increase in ozone-utilization efficiency (ΔCOD/ΔO 3 = 2.12) compared to that of pure ozonation (0.96). These findings highlight catalysts supported on Ni CAF as a facile and efficient approach to achieve both high catalytic activity and excellent structural stability, demonstrating that they are highly viable for practical applications.