Non-oxidative methane coupling has promising economic potential, but the catalytic and radical reactions become complicated at high temperatures. Here, we investigate the mechanism of non-oxidative methane coupling on an iron single-atom catalyst using density functional theory, and evaluate the catalytic performance under various reaction conditions using microkinetic modelling and experiments. Under typical reaction conditions (1300 K and 1 bar), C–C coupling and subsequent dehydrogenation to produce ethylene shows comparable energetics between the gas-phase and catalytic pathways. However, the microkinetic analysis reveals that the iron single-atom catalyst converted methane to mainly CH₃ and H₂ at reaction temperatures above 1300 K, and acetylene production is dominant over ethylene production. The sensitivity analysis suggests that increasing the C₂ hydrocarbon yield by optimising the reaction conditions is limited. The experimental results obtained at 1293 K are consistent with the theoretical estimation that acetylene is the main C₂ product over the iron single-atom catalyst.

非氧化甲烷偶联具有广阔的经济潜力，但催化和自由基反应在高温下变得复杂。在这里，我们利用密度泛函理论研究了铁单原子催化剂上非氧化甲烷偶联的机理，并利用微动力学模型和实验评估了各种反应条件下的催化性能。在典型的反应条件下（1300 K 和 1 bar），C-C 偶联和随后的脱氢生产乙烯显示出气相和催化途径之间相当的能量学。然而，微动力学分析表明，铁单原子催化剂在高于1300 K的反应温度下将甲烷主要转化为CH ₃和H ₂ ，并且乙炔的产生比乙烯的产生占主导地位。敏感性分析表明通过优化反应条件来提高C ₂烃产率是有限的。在1293 K下获得的实验结果与铁单原子催化剂上乙炔是主要C ₂产物的理论估计一致。