This work reports the synthesis and characterization of mesoporous cobalt-nickel mixed metal oxide catalysts with varying Co:Ni ratios using an inverse micelle template self-assembly method. Their structural and morphological properties and catalytic performance in styrene epoxidation were evaluated. Among them, the 73CoNi-250 catalyst (Co: Ni70:30 mol/mol%, calcined 250°C) exhibited a unique flower-like morphology and the highest surface area, which XPS analysis linked to a higher concentration of oxygen vacancies. Notably,73CoNi-250 demonstrated exceptional catalytic activity for styrene epoxidation, achieving near-complete styrene conversion (>99 %) and high selectivity (94 %) for styrene epoxide under mild reaction conditions without the need for oxidants such as peroxides. Furthermore, the catalyst exhibited excellent reusability (≥ 4 cycles) without significant activity loss or changes in mesoporosity. Kinetic studies revealed a first-order reaction profile and a significantly enhanced rate constant compared to the best-reported values (fivefold) in the literature, further underlining the catalyst's efficiency, and emphasizing the environmentally friendly approaches in chemical synthesis.
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