Comparative study on the direct decomposition of nitrous oxide over M (Fe, Co, Cu)-BEA zeolites
Comparative study on the direct decomposition of nitrous oxide over M (Fe, Co, Cu)-BEA zeolites
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M(Fe,Co,Cu)-BEA沸石直接分解一氧化二氮的对比研究
DOI：
10.1016/j.jcat.2012.07.008
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发表时间：
2012-10-01
影响因子：
7.3
通讯作者：
Li, Yingxia
中科院分区：
文献类型：
--
作者：
Liu, Ning;Zhang, Runduo;Li, Yingxia
采用密度泛函理论（DFT）和实验相结合的方法，系统地研究了M（Fe，Cu，Co）-β（Ⅵ）分子筛对N_2O直接分解的催化活性。本征动力学计算结果与密度泛函理论计算结果和微观动力学分析结果吻合较好，表明M-O2的独特脱附能垒是M-O2脱附的主要原因（第三部分）。在DFT计算过程中，只有Co-Al 2 O3上生成了一个独特的中间体（IM），活性评价和N2 O-TPD实验证实了这一点，表明IM的形成降低了Co-Al 2 O3的N2 O分解速率。随后通过微动力学分析研究了IM的负面影响，通过微动力学分析可知，Co-N2的第二正反应速率常数低于其逆反应速率常数，导致N2 O分解速率最终下降。(C)2012 Elsevier Inc. All rights reserved.
Catalytic activities of M (Fe, Cu, Co)-beta (BEA) zeolites for N2O direct decomposition were systematically investigated by employing both experimental and theoretical [density functional theory (DFT)] approaches. The activities of M-BEA determined by intrinsic kinetic evaluations are in good agreement with the DFT calculations and the microkinetic analyses, revealing that the distinguishing activities of M-BEA were mainly attributed to their distinct energy barriers for the O-2 desorption (Part 3). During the DFT calculations, a unique intermediate (IM) was generated only over Co-BEA, which was verified by the activity evaluation and N2O-TPD experiments, showing that the formation of IM reduced N2O decomposition rate of Co-BEA. The negative effect of the IM was thereafter investigated by the microkinetic analyses through which it was known that the second forward reaction rate constant of Co-BEA was lower than its reverse reaction rate constant, resulting in a final decline of the N2O decomposition rate. (C) 2012 Elsevier Inc. All rights reserved.