Mesoporous MgO·Al2O3 nanopowder-supported meso–macroporous nickel catalysts: a new path to high-performance biogas reforming for syngas

Abstract

Mesoporous nanocrystalline MgO·Al₂O₃ powders with different MgO/Al₂O₃ molar ratios were synthesized by a new and simple sol–gel route using C₃H₆O (propylene oxide) as a gelation agent. The prepared powders were employed as a support for preparation of 10 wt% Ni catalysts in biogas reforming, for the production of synthesis gas. This simple sol–gel method led to the preparation of powders with high BET surface area in the range of 252.8–301.6 m² g⁻¹ depending on the MgO/Al₂O₃ molar ratio after calcination at 700 °C. The samples also exhibited narrow single modal pore size distributions in the mesopore region. The H₂-TPR analysis revealed that increasing the MgO/Al₂O₃ molar ratio shifted the T_max of the reduction peaks to higher temperature, indicating the lower reducibility of the prepared catalysts with high MgO content. The NH₃-TPD also confirmed the increase in basicity of the prepared samples with increasing MgO/Al₂O₃ molar ratio. The prepared catalysts exhibited high potential as catalysts for biogas reforming with high stability, and the catalysts with higher content of MgO showed higher resistance against carbon formation.