Hydrogen-rich syngas production from bi-reforming of greenhouse gases over zirconia modified Ni/MgO catalyst

Bi-reforming of methane (BRM) is gaining an increase interest due to the critical requirements to mitigate global warming and provide alternative energy resources. However, there has been a serious challenge to the scale-up of the process to commercial production due to the catalyst deactivation. In the present study, the influence of ZrO₂ modifications on the activity and stability of MgO-supported Ni catalyst in the BRM reaction was investigated. The ZrO₂-MgO mixed oxide support was prepared by co-precipitation method with variation in the ZrO₂ composition and subsequently impregnated with Ni. The characterization of the freshly prepared Ni/MgO and Ni/MgO-ZrO₂ catalysts using N₂ physisorption analysis, X-Ray Diffraction (XRD), FESEM, XPS, H₂-TPR, and CO₂-TPD techniques revealed suitable physicochemical properties for the BRM reaction. The Ni/MgO-ZrO₂ catalysts showed an improved performance in the BRM reaction in terms of activity and stability compared to the Ni/MgO at 800°C and CH₄, H₂O, CO₂ ratio of 3:2:1, respectively. The best performance was obtained using the Ni/15%ZrO₂-MgO for the BRM with CO₂ and CH₄ conversion of 81.5% and 82.5%, respectively. The characterization of the spent Ni/MgO catalyst using Raman spectroscopy, FESEM, and High Resolution Transmission Electron Microscopy (HRTEM) analysis revealed the formation of amorphous carbon that could be responsible for its fast deactivation.