Heterogeneous Fe(3) single-cluster catalyst for ammonia synthesis via an associative mechanism.
Heterogeneous Fe(3) single-cluster catalyst for ammonia synthesis via an associative mechanism.
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DOI：
10.1038/s41467-018-03795-8
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发表时间：
2018-04-23
影响因子：
16.6
通讯作者：
Li J
中科院分区：
文献类型：
--
作者：
Liu JC;Ma XL;Li Y;Wang YG;Xiao H;Li J
目前的工业氨合成工艺依赖于Haber-Bosch过程，该过程由解离机理引发，其中吸附的N2直接解离，因此受到Brønsted-Evans-Polanyi（BEP）关系的限制。本文从第一性原理理论研究和微观动力学分析两个方面提出了一种新的合成氨多相催化剂的设计思路，即在θ-Al 2 O3（010）表面锚定Fe 3团簇。本文研究了Fe_3/θ-Al_2 O_3（010）催化剂上N_2转化为N_3的反应机理，发现吸附的N_2首先被氢化为NNH的缔合机理优于解离机理，这与Fe_3团簇的大自旋极化、低氧化态和多步氧化还原能力有关。缔合机理使氨生成的转换频率（TOF）从BEP关系的限制中解放出来，计算的Fe 3/θ-Al 2 O 3（0 10）上的TOF与Ru B5位相当。目前的工业氨合成依赖于Haber-Bosch工艺，该工艺受到Brønsted-Evans-Polanyi关系的限制。本文通过第一性原理计算和微观动力学分析，提出了一种将Fe 3固定在θ-Al 2 O3（010）表面作为非均相单簇催化剂的新策略。
The current industrial ammonia synthesis relies on Haber–Bosch process that is initiated by the dissociative mechanism, in which the adsorbed N2 dissociates directly, and thus is limited by Brønsted–Evans–Polanyi (BEP) relation. Here we propose a new strategy that an anchored Fe3 cluster on the θ-Al2O3(010) surface as a heterogeneous catalyst for ammonia synthesis from first-principles theoretical study and microkinetic analysis. We have studied the whole catalytic mechanism for conversion of N2 to NH3 on Fe3/θ-Al2O3(010), and find that an associative mechanism, in which the adsorbed N2 is first hydrogenated to NNH, dominates over the dissociative mechanism, which we attribute to the large spin polarization, low oxidation state of iron, and multi-step redox capability of Fe3 cluster. The associative mechanism liberates the turnover frequency (TOF) for ammonia production from the limitation due to the BEP relation, and the calculated TOF on Fe3/θ-Al2O3(010) is comparable to Ru B5 site. The current industrial ammonia synthesis relies on the Haber-Bosch process that is limited by the Brønsted–Evans–Polanyi relation. Here, the authors propose a new strategy that an anchored Fe3 on θ-Al2O3(010) surface serves as a heterogeneous single cluster catalyst for ammonia synthesis from first-principles calculations and microkinetic analysis.
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影响因子：
15
作者：
Grubel, Katarzyna;Brennessel, William W.;Mercado, Brandon Q.;Holland, Patrick L.
通讯作者：
Holland, Patrick L.
影响因子：
15
作者：
Čorić I;Holland PL
通讯作者：
Holland PL
影响因子：
62.1
作者：
Hoffman, Brian M.;Lukoyanov, Dmitriy;Yang, Zhi-Yong;Dean, Dennis R.;Seefeldt, Lance C.
通讯作者：
Seefeldt, Lance C.
影响因子：
4.8
作者：
Fedoseev, G.;Cuppen, H. M.;Linnartz, H.
通讯作者：
Linnartz, H.
影响因子：
5.3
作者：
Abghoui, Younes;Skulason, Egill
通讯作者：
Skulason, Egill