Chemical hydrogen storage via conversion with carbon dioxide into methane is a promising technology in an energy system that relies on renewable energy resources. Robust heterogeneous catalysts are needed for this reaction to proceed at relevant levels. Ni/MgO is a promising catalyst in terms of activity and stability. Although several microscale catalyst studies exist, there is a lack of knowledge on catalyst performance and reactor control at larger scale for carbon dioxide methanation at ambient pressure and a technically relevant stoichiometric H₂:CO₂ (4:1) feed. Two catalysts with a loading of 11 and 17 wt.% nickel were prepared by wet impregnation, producing a Ni/MgO solid solution with a cubic lattice. Controlled increase (‘scanning experiment’) of the catalyst temperature to 500 °C for the highly exothermic CO₂ methanation was compared to steady-state experiments. Scanning and steady-state experiments yield comparable results in terms of carbon dioxide conversion and methane selectivity, whereas scanning experiments lead to considerable time saving. At a moderate temperature of 325 °C and a feed flow consisting of H₂:CO₂:N₂ = 4:1:5 at a flow rate of 250 cm³ _STPmin⁻¹, CO₂ conversion and CH₄ selectivity near thermodynamic equilibrium are achievable. The long-term stability of Ni/MgO (17 wt.% Ni) at 330 °C was proven during reactor operation for several days.

通过将二氧化碳转化为甲烷来存储化学氢是依赖可再生能源的能源系统中的一项有前途的技术。为了使该反应在相关水平上进行，需要鲁棒的非均相催化剂。就活性和稳定性而言，Ni / MgO是一种有前途的催化剂。尽管已经进行了几项微型催化剂研究，但缺乏有关在常压下甲烷化甲烷化和技术上相关的化学计量H ₂：CO _2的催化剂性能和大规模反应器控制的知识（4：1）喂食。通过湿法浸渍制备两种镍含量为11和17重量％的催化剂，产生具有立方晶格的Ni / MgO固溶体。将高放热的CO ₂甲烷化反应将催化剂温度控制升高（“扫描实验”）至500°C与稳态实验进行了比较。扫描和稳态实验在二氧化碳转化率和甲烷选择性方面产生可比的结果，而扫描实验可节省大量时间。在325°C的中等温度下，进料流由H ₂：CO ₂：N ₂  = 4：1：5组成，流速为250 cm ³  _STP min ^-1，CO ₂可以实现接近热力学平衡的转化率和CH ₄选择性。Ni / MgO（Ni的17 wt。％）在330°C的长期稳定性在反应器运行数天的过程中得到了证明。