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氮掺杂碳纳米管(NCNTs)作为载体负载铁(Fe)纳米颗粒,可应用于CO_2多相催化加氢反应(633 K和25 bar)。当将钾(K)和锰(Mn)作为助催化剂时,Fe/NCNT展现出优异的CO_2加氢性能,在体积空速(GHSV)为3.1 L·g~(–1)·h~(–1)时转化率可达34.9%。当使用K作为助催化剂时,反应对烯烃和短链烷烃具有高的选择性。当K和Mn同时作为助催化剂时,其催化活性能够稳定地维持60 h。助催化剂Mn的结构效应通过X射线衍射、氢气程序升温还原以及近边X射线吸收精细结构进行表征。助催化剂Mn不仅能够稳定中间态FeO,且能降低程序升温还原的起始温度。通过探针反应NH3的催化分解来表征助催化剂效应。当K和Mn作为助催化剂时,Fe/NCNT具有最好的催化活性。在还原条件下,当K作为助催化剂时,Fe/NCNT具有最优异的热稳定性。
Nitrogen-doped carbon nanotubes (NCNTs) as supported iron (Fe) nanoparticles can be applied to CO 2 heterogeneous catalytic hydrogenation (633 K and 25 bar). When potassium (K) and manganese (Mn) were used as cocatalysts, Fe / NCNT exhibited excellent CO_2 hydrogenation performance. Under GHSV of 3.1 L · g -1 · h ~ (- 1) conversion rate of up to 34.9%. When K is used as a cocatalyst, the reaction has high selectivity to olefins and short-chain alkanes. When K and Mn act as cocatalysts simultaneously, their catalytic activities can be stably maintained for 60 h. The structural effect of the promoter Mn was characterized by X-ray diffraction, hydrogen temperature reduction and near-edge X-ray absorption fine structure. The promoter Mn can not only stabilize the intermediate FeO, but also reduce the initial temperature of the programmed temperature reduction. The cocatalyst effect was characterized by the catalytic decomposition of the probe reaction NH3. Fe / NCNT has the best catalytic activity when K and Mn are used as cocatalysts. Under reducing conditions, Fe / NCNT has the most excellent thermal stability when K acts as a co-catalyst.