Abstract A bifunctional Ni/MgO catalyst was prepared to catalyze CO2 methanation and make use of CO2 as an abundant hydrogen storage facility. The effect of Ni loading and MgO quality on the rate of methanation was tested in a temperature range of 533–648 K. The Ni loading was varied between 0 to 27 wt.% on MgO. To investigate the impact of matrix elements, a MgO/CaO support was tested with 21 wt.% nickel loading. Further, the role of MgO in the bifunctional catalyst was proven. The reaction kinetics was modeled with a Langmuir–Hinshelwood approach considering the bifunctional character of the catalyst. Nickel provides the adsorbent capacity for hydrogen and is highly selective for methane. MgO activates CO2 through chemisorption. Increasing Ni loading of the catalyst increased the rate of CO2 conversion. According to the results, the mechanism of CO2 methanation did not change with Ni loading. The Ni/MgO catalyst acted as a robust, active and highly selective catalyst for CO2 methanation. With CO2 conversion of 87%, the selectivity to methane was ≥99%. Besides excellent catalytic activity the catalysts suffice the necessity of simple catalyst preparation, usage and recyclability for industrial applicability of CO2 methanation.

中文翻译：

---

双功能Ni/MgO催化剂上CO2甲烷化反应动力学

摘要 制备了一种双功能Ni/MgO催化剂来催化CO2甲烷化，并将CO2用作储氢设施。在 533-648 K 的温度范围内测试了 Ni 负载和 MgO 质量对甲烷化速率的影响。 Ni 负载在 MgO 的 0 到 27 wt.% 之间变化。为了研究基体元素的影响，测试了 MgO/CaO 载体，其中镍负载量为 21 wt.%。此外，证明了 MgO 在双功能催化剂中的作用。考虑到催化剂的双功能特性，反应动力学采用 Langmuir-Hinshelwood 方法建模。镍为氢气提供吸附能力，对甲烷具有高度选择性。MgO 通过化学吸附活化 CO2。增加催化剂的 Ni 负载量会增加 CO2 转化率。根据结果​​，CO2 甲烷化的机理不随 Ni 负载量而改变。Ni/MgO 催化剂在 CO2 甲烷化过程中起到了稳定、活性和高选择性的作用。CO2 转化率为 87%，对甲烷的选择性≥99%。除了优异的催化活性外，该催化剂还满足了简单的催化剂制备、使用和可回收性对 CO2 甲烷化的工业适用性的必要性。