Optimization of greenhouse gas valorization over ceria-promoted Co–Ni/graphene oxide catalytic materials using response surface methodology

Abstract

Background

The mitigation of global warming effect requires intensified research efforts to reduce greenhouse gas emissions. This study was aimed at investigating the valorization of two principal greenhouse gases, namely carbon dioxide (CO₂) and methane (CH₄), over CeO₂-doped Co–Ni/GO catalytic materials. The CeO₂-doped Co–Ni/GO catalysts were synthesized using a sequential wet impregnation method and employed for CO₂ reforming of CH₄. The catalytic materials were characterized using various instrumental techniques. Response surface methodology (RSM) was employed to investigate the impact of process factors, namely reaction temperature (ranging from 700 to 800 °C), CeO₂ loading (ranging from 5% to 15%) and feed flowrate (ranging from 10n to 50 mL min⁻¹), on the CH₄ conversions.

Results

The three factors were observed to have significant influence on the CH₄ conversion based on analysis of variance. The analysis of the RSM quadratic model revealed that the optimum conditions of 800 °C, 14.22% and 10.00 mL min⁻¹ were obtained for the reaction temperature, CeO₂ loading and feed flowrate resulting in maximum CH₄ conversion of 98.24%. The desirability function for these results was calculated to be 0.934. The predicted process parameters aligned with the results of the actual experimental analysis.

Conclusion

This study has demonstrated that the conversion of CH₄ to value-added products such as syngas can be optimized using RSM. The optimum conditions obtained could be used to improve the process performance. © 2024 Society of Chemical Industry (SCI).