Thermal dry reforming of methane over La₂O₃ co-supported Ni/MgAl₂O₄ catalyst for hydrogen-rich syngas production

The excess emission of greenhouse gases (GHGs) such as CO₂ and CH₄ is posing an acute threat to the environment, and efficient ways are being sought to utilize GHGs to produce syngas (H₂, CO) and lighter hydrocarbons (HCs). In this study, the dry reforming of methane (DRM) has been carried out at 700 °C using La₂O₃ co-supported Ni/MgAl₂O₄ nano-catalyst in a fixed bed thermal reactor. The catalyst is characterized using various techniques such as XRD, FESEM, EDX-mapping, CO₂-TPD, H₂-TPR and TGA. The modified MgAl₂O₄ shows the flake type structure after the addition of La₂O₃. The TPR and TPD analysis shows the highly dispersed metal and strong basic nature of the catalyst consequently enhances the conversion of CO₂ and CH₄. The highest conversion for CH₄ is 87.3% while CO₂ conversion is nearly 89.5% in 20 h of operation time. The selectivity of H₂ and CO approached 50% making the H₂/CO ratio above unity. In the longer time-on-stream (TOS) test, the catalyst shows elevated potential for longer runs showcasing better catalytic activity. The stability of the catalyst is indicated via a proposed reaction mechanism for DRM in operating conditions. Moreover, TGA indicates the lower weight loss of spent catalyst which ascribed the lower formation of carbon during TOS 20 h.