CO2 reforming of CH4 over Ni/mesostructured silica nanoparticles (Ni/MSN)

Abstract

The development of supported Ni-based catalysts for CO₂ reforming of CH₄ was studied. Ni supported on mesostructured silica nanoparticles (MSN) and MCM-41 were successfully prepared using an in situ electrochemical method. The N₂ physisorption results indicated that the introduction of Ni altered markedly the surface properties of MCM-41 and MSN. The TEM, H₂-TPR and IR adsorbed CO studies suggested that most of the Ni deposited on the interparticles surface of MSN have higher reducibility than Ni plugged in the pores of MCM-41. Ni/MSN showed a higher conversion of CH₄ at about 92.2% compared to 82.6% for Ni/MCM-41 at 750 °C. After 600 min of the reaction, Ni/MCM-41 started to deactivate due to the formation of shell-like carbon which may block the active sites and/or surface of catalyst, as proved by TEM analyses. Contrarily, the activity of Ni/MSN was sustained for 1800 min of the reaction. The high activity of Ni/MSN was resulted from the presence of greater number of easily reducible Ni on the surface. In addition, the large number of medium-basic sites in Ni/MSN was capable to avoid the formation of shell-like carbon that deactivated the catalyst, thus increased the stability performance. The results presented herein provide new perspectives on Ni-based catalysts, particularly in the potential of MSN as the support.