The catalytic reduction of CO₂ to methane, called CO₂ methanation or the Sabatier reaction, is a reversible and exothermic reaction. A mean field microkinetic model is developed for the Sabatier reaction on Ru catalyst at atmospheric pressure and validated with reactor simulations in this work. The mechanism comprised of elementary steps occurring on the catalyst surface is devised based on spectroscopic findings and DFT calculations reported in the literature. The initial parameter values are taken from DFT literature or computed using UBI-QEP. The model is fitted to limited experimental data points from only one source in the literature. The resulting model reliably predicts experimental data from multiple sources in the literature for CO₂ methanation on Ru at various feed ratios in the temperature range of 250–490 °C as well as the equilibrium conversion of CO₂. Microkinetic analyses under the relevant conditions revealed that the reaction proceeds via the CO₂* → CO* → C* → CH_x* pathway on Ru catalyst.

中文翻译：

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钌上CO ₂甲烷化的微观动力学建模与分析

将CO ₂催化还原为甲烷，称为CO ₂甲烷化或Sabatier反应，是可逆的放热反应。针对大气压下Ru催化剂上的Sabatier反应建立了平均场微动力学模型，并在此工作中通过反应器模拟对其进行了验证。基于光谱发现和文献报道的DFT计算，设计了由在催化剂表面上发生的基本步骤组成的机理。初始参数值取自DFT文献或使用UBI-QEP计算。该模型仅适用于文献中一个来源的有限实验数据点。所得模型可靠地预测了文献中来自CO _2的多个来源的实验数据在250-490°C的温度范围内，以不同的进料比对Ru进行甲烷化，以及CO ₂的平衡转化率。在相关条件下的微动力学分析表明，反应通过Ru催化剂上的CO ₂ *→CO *→C *→CH _x *途径进行。