Molybdenum-promoted cobalt supported on SBA-15: Steam and sulfur dioxide stable catalyst for CO oxidation

Abstract

It was studied a benign one-pot synthesis of a steam and SO2 stable molybdenum promoted cobalt catalyst supported on SBA-15 for CO oxidation runs at 730 ̊C. The physicochemical properties of the catalyst were analyzed by XRD, SEM/HRTEM, UV–vis, Raman spectroscopy, XPS, H2-TPR, and NH3-TPD. Well-dispersed Co3O4 and, molybdenum species allowed to maintain CO conversion close to 90 % against 55 % over the non-Mo-promoted Co-catalyst. That promising behavior was attributed to the strong Co-Mo interaction that improved the acidic properties, which strongly decreased deactivation by SO2 and water steam. The impregnated catalyst presented formation of aggregated MoO3 species and Co3O4 mainly inside the SBA-15 mesopores, leading to lower CO oxidation activity and lower catalytic stability in the presence of the above interfering compounds. Thus, the one-pot prepared molybdenum promoted cobalt catalyst supported over mesoporous silica SBA-15 emerges as a potential alternative to substitute CO oxidation catalysts based on noble metals.