Reduced Siderite Ore Combined with Magnesium Oxide as Support Material for Ni-Based Catalysts; An Experimental Study on CO₂ Methanation

Ni-based catalysts play a fundamental role in catalytic CO₂ methanation. In this study, the possibility of using siderite ore as a catalyst or catalytic support material for nickel-based catalysts was investigated, aiming at the exploitation of an abundant natural resource. The catalytic performance of Ni-based catalysts with reduced siderite ore as a support was evaluated and compared to MgO as a support material. MgO is known as an effective support material, as it provides access to bifunctional catalysts because of its basicity and high CO₂ adsorption capacity. It was shown that undoped and Ni-doped reduced siderite ore have comparable catalytic activity for CO₂ hydrogenation (20−23%) at 648 K, but show limited selectivity toward methane (<20% for siderite_reduced and 60.2% for Ni/siderite_reduced). When MgO was added to the support material (Ni/siderite_reduced/MgO), both the CO₂ conversion and the selectivity toward methane increased significantly. CO₂ conversions were close to the thermodynamic equilibrium, and methane selectivities of ≥99% were achieved.