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 FeMnO₃ with Na₂WO₄, with good cycling performance, achieving a high space time yield of 29.8 g_C2-C3 kg_cat.^-1 h^-1 with 20% CH₄ conversion and 80% C₂-C₃ selectivity at 800 ^oC and a low catalyst/CH₄ weight ratio of 13.5. CL-OCM process is established by “FeMnO₃↔[MnFe₂O₄ + MnO]” red-ox cycle. Na₂WO₄-decoration gets lattice oxygen stored in FeMnO₃ transformed 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.

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，因为它允许反应通过在两个反应器中重复还原-氧化循环进行。它需要一种具有足够高选择性 CH ₄转化晶格氧承载能力的突破性催化剂，但这代表了一个巨大的挑战。在此，我们报道了一种通过用 Na ₂ WO ₄修饰氧载体 FeMnO ₃获得的高效催化剂，该催化剂具有良好的循环性能，实现了 29.8 g _C2-C3 kg _cat的高时空产率_。^-1 h ^-1具有 20% CH ₄转化率和 80% C ₂-C ₃选择性在 800 ^o C 和低催化剂/CH ₄重量比为 13.5。CL-OCM 过程是通过“FeMnO ₃ ↔[MnFe ₂ O ₄ + MnO]”氧化还原循环建立的。Na ₂ WO _{4 -}修饰使储存在FeMnO _{3 中的}晶格氧从非选择性转变为选择性，这是由于晶格氧析出的减缓。使用 10 克催化剂放大的 CL-OCM 测试也产生了在使用 1 克催化剂的情况下看到的类似结果，验证了巨大的应用潜力。