Ni-Induced C-Al2O3-Framework (NiCAF) Supported Core-Multishell Catalysts for Efficient Catalytic Ozonation: A Structure-to-Performance Study

During catalytic ozonation, Al2O3-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-Al2O3-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 Al2O3-supported catalysts and Al2O3 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 center dot OH-production efficiency and an 86% increase in organic-adsorption capacity compared to Al2O3-supported catalysts. During the long-term treatment of coal-gasification wastewater (similar to 5 m(3) day(-1)), the pilot-scale demonstration of CuCo/(Ni)CAF-catalyzed ozonation revealed a 120% increase in ozone-utilization efficiency (Delta COD/Delta O-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.