Ni-based Catalyst Development for the Catalytic Conversion of CO₂ to Substitute Natural Gas—Effect of Preparation Method

Substitute Natural Gas (SNG) is receiving discernible attention as a fuel for the next generations because of the growing energy demand, and fossil fuels are depleting. On the other hand, CO₂ emissions are already increasing, so catalytic conversion of CO₂ to SNG is a promising way to reduce atmospheric CO₂. However, CO₂ conversion is not so easy because of its stable properties. So, there is a need for a suitable catalyst that can solve problems such as CO₂ conversion, CH₄ yield, catalyst deactivation and related issues. Here, we report the effect of the catalyst preparation method and the effect of precipitating agents on the problems mentioned earlier. The 5 series of Al₂O₃-supported Ni-based and Ni–Fe bimetallic catalysts are prepared by impregnation and coprecipitation methods and characterized by H₂-TPR, XRD, H₂-TPD, and CO₂-TPD, NH₃-TPD techniques. The reactions are carried out with TPSR by using a pulse injection technique, which showed a range of CH₄ formation and CO₂ conversion with a CO₂:H₂ ratio of 1:4. The 15(Ni–Fe)/Al₂O₃ showed almost 2 times better conversion and 1.5 times yield at a lower temperature (300 °C) compared to the other prepared catalysts. These findings are promising and suggest that Ni–Fe catalysts prepared by coprecipitation method are favoured for SNG production and could lead to more efficient and cost-effective process development.