Xiao Peipei, Tang Xiaomin, Toyoda Hiroto, Wang Yilin, Zheng Anmin, Wang Lizhuo, Huang Jun, Sawada Masato, Nakamura Kengo, Wang Yong, Gies Hermann, Yokoi Toshiyuki
Institute of Integrated Research, Institute of Science Tokyo, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
State Key Laboratory of Magnetic Resonance Spectroscopy and Imaging, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China.
Angew Chem Int Ed Engl. 2025 Aug 11;64(33):e202506023. doi: 10.1002/anie.202506023. Epub 2025 Jun 25.
Transition-metal-free aluminosilicate FER-type zeolite has been demonstrated to effectively catalyze methane to methanol using NO as the oxidant with distorted tetra-coordinated aluminum (Al) and penta-coordinated aluminum (Al) as potential active sites. However, the specific effects of Al distribution on the active Al species have not been thoroughly investigated. Herein, aluminosilicate FER-type zeolites with controllable Al distribution were developed. Al distribution, including the arrangement and location of Al atoms, was characterized using Al MQMAS/MAS and Si MAS NMR spectra. The arrangement of aluminum, particularly the isolated Al and paired Al in as-synthesized samples, influenced the proximity between oxidative and acidic sites in H-type samples. Al locations involved the specific positioning of bifunctional sites and affected the final product. The increased CH conversion at 250-275 °C of FER zeolite with Al preferential population at T4 sites confirmed the higher activity of Al species from T4 sites. Additionally, a higher proportion of Al atoms in 10-ring channels facilitated the tandem conversion of methane to methanol on oxidative sites, followed by methanol to hydrocarbons on acidic sites at 300-375 °C. This study corroborated and expanded upon our recent research and highlighted the significant impact of Al distribution in FER zeolite on methane oxidation.
无过渡金属的FER型铝硅酸盐沸石已被证明能以NO为氧化剂，将甲烷有效催化转化为甲醇，其中扭曲的四配位铝（Al）和五配位铝（Al）作为潜在的活性位点。然而，Al分布对活性Al物种的具体影响尚未得到充分研究。在此，我们开发了Al分布可控的FER型铝硅酸盐沸石。利用Al MQMAS/MAS和Si MAS NMR光谱对Al分布进行了表征，包括Al原子的排列和位置。铝的排列，特别是合成样品中的孤立Al和成对Al，影响了H型样品中氧化位点和酸性位点之间的距离。Al的位置涉及双功能位点的特定定位，并影响最终产物。FER沸石在250-275°C下CH转化率的提高证实了T4位点的Al物种具有更高的活性，其中Al优先占据T4位点。此外，10元环通道中较高比例的Al原子促进了甲烷在氧化位点上串联转化为甲醇，随后在300-375°C下甲醇在酸性位点上转化为烃类。这项研究证实并扩展了我们最近的研究，并突出了FER沸石中Al分布对甲烷氧化的重大影响。
