An Oxygen Carrier Catalyst Toward Efficient Chemical Looping-oxidative Coupling of Methane
An Oxygen Carrier Catalyst Toward Efficient Chemical Looping-oxidative Coupling of Methane
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DOI：
10.1016/j.apcatb.2021.120948
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
Weidong Sun;Guofeng Zhao;Ya Gao;Jiaqi Si;Ye Liu;Yong Lu
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文献类型：
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作者：
Weidong Sun;Guofeng Zhao;Ya Gao;Jiaqi Si;Ye Liu;Yong Lu
化学循环概念为本质安全和高效的甲烷氧化偶联（CL-OCM）工艺铺平了道路，因为它允许反应在两个反应器中通过重复的还原-氧化循环进行。这就需要一种具有足够高的选择性甲烷转化晶格氧携带能力的突破性催化剂，但这是一个巨大的挑战。本文中，我们报道了通过用Na 2 WO 4修饰氧载体FeMnO 3可获得的高效催化剂，其具有良好的循环性能，在800 °C下实现了29.8gC2-C3 kgcat. -1h-1的高时空产率，20%CH4转化率和80%C2-C3选择性，以及13.5的低催化剂/CH 4重量比。CL-OCM工艺是通过“FeMnO 3参与[MnFe 2 O 4 + MnO]”氧化还原循环建立的。Na_2WO_4修饰使FeMnO_3中晶格氧的析出由非选择性转变为选择性。使用10克催化剂的放大CL-OCM测试也产生了与使用1克催化剂的情况相当的结果，验证了巨大的应用潜力。
Chemical looping concept paves way toward intrinsically safe and efficient oxidative coupling of methane (CL-OCM) process, because it permits the reaction to proceed via repeating reduction-oxidation cycle in two reactors. It is calling for a ground-breaking catalyst with enough high selective CH4-converting lattice-oxygen carrying capacity but represents a grand challenge. Herein, we report an efficient catalyst obtainable by decorating an oxygen carrier FeMnO3with Na2WO4, with good cycling performance, achieving a high space time yield of 29.8 gC2-C3kgcat.−1h−1with 20% CH4conversion and 80% C2-C3selectivity at 800 °C and a low catalyst/CH4weight ratio of 13.5. CL-OCM process is established by “FeMnO3↔ [MnFe2O4+ MnO]” redox cycle. Na2WO4-decoration gets lattice oxygen stored in FeMnO3transformed from non-selective to selective due to mitigation of lattice-oxygen evolution. Scaled up CL-OCM testing with 10-gram catalyst also yields comparable results seen in the case of using 1-gram catalyst, validating great application potential.