N2O is a greenhouse gas and a candidate oxidant. Volatile organic pollutants (VOCs) have caused great harm to the atmospheric ecological environment. Developing the technique utilizing N2O as the oxidant to oxidize VOCs to realize the collaborative purification has significant importance and practical value for N2O emission control and VOC abatement. Therefore, the study of N2O catalytic oxidation of tert-butanol based on zeolite catalysts was carried out. A series of molecular sieves, including FER, MOR, ZSM-5, Y, and BEA, were selected as the catalyst objects, and the 1.5% wt Fe and Co were, respectively, loaded on the zeolite catalysts via the impregnation method. It was found that the catalytic performance of BEA was the best among the molecular sieves. Comparing the catalytic performance of Fe-BEA under different load gradients (0.25~2%), it was found that 1.5% Fe-BEA possessed the best catalytic activity. A series of characterization methods showed that Fe3+content in 1.5% Fe-BEA was the highest, and more active sites formed to promote the catalytic reaction. The α-O in the reaction eventually oxidized tert-butanol to CO2over the active site. The Co mainly existed in the form of Co2+cations over Co-BEA samples; the 2% Co-BEA possessing higher amounts of Co2+exhibited the highest activity among the prepared Co-BEA samples.
Yulai Lin,Jun Liang,Zijun Huang,Jiaming Dong,Yongming Luo,Dedong He
Cobalt-based catalysts have garnered significant attention in propane dehydrogenation (PDH) due to their cost-effectiveness and environmental compatibility, where the properties of Co species dictate catalytic performance. However, conventional synthesis methods fail to simultaneously achieve precise encapsulation and structural stabilization of Co sites under harsh PDH conditions. Herein, we propose an innovative dual-anchoring strategy that synergizes strong electrostatic adsorption (SEA) and secondary crystallization (SC) to engineer highly stable yet active Co centers at low metal loadings (0.145 wt%). The SEA process enabled directional anchoring of Co precursors within silanol nests of dealuminated BEA zeolite, while SC treatment prevented Co aggregation. This synergistic approach yielded tetrahedral Co²⁺ (Td-Co²⁺) sites with exceptional dispersion and optimized Lewis acidity, achieving stable PDH operation for 110 hours with specific activity surpassing most reported catalysts.
Propylene is a key chemical. Propane dehydrogenation (PDH) over non-noble cobalt catalysts suffers rapid deactivation from sintering and coking. Herein, we report a core–shell catalyst (1.0Co/BEA@ x Si) with a mesoporous silica shell on Co-impregnated dealuminated Beta zeolite. The silica shell enhances Co dispersion and modulates Co reduction: it promotes the formation of active tetrahedral Co 2+ sites from Co 3 O 4 while suppressing over-reduction to metallic Co 0 . The optimized 1.0Co/BEA@1.0Si maintains ~99% propylene selectivity and achieves a formation rate of 71.0 gC 3 H 6 ·g Co −1 ·h −1 after 980 min, far surpassing uncoated 1.0Co/BEA and most reported Co-based PDH catalysts. In situ and post-reaction analyses show the shell strengthens propane adsorption/activation and reduces coke formation. Core–shell engineering thus stabilizes active metal states via local redox microenvironment modulation, offering new design principles for robust alkane dehydrogenation catalysts.
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