A comparative study on catalytic performances of chromium incorporated and supported mesoporous MSU-x catalysts for the oxidehydrogenation of ethane to ethylene with carbon dioxide

摘要

Two kinds of Cr-based mesoporous materials,Cr incorporated and supported silicate MSU-1,were synthesized at room temperature and characterized with XRD,N_2 adsorption-desorption,FT-IR,DR UV-vis and H_2-TPR techniques.Both Cr-based catalysts exhibited similar mesoporous channels and textural properties.The catalytic performances of two catalysts for the oxidative dehydrogenation of ethane to ethylene with CO_2 were investigated.They both showed high activities,providing 58.0 and 68.1% ethane conversion and 53.4 and 55.6% ethylene yield at 700 deg C,respectively.The catalysts were prone to deactivate in the reaction but could be partially regenerated by oxygen.Cr species formed in high oxidation state were reduced during the reaction.It was proposed that these high-valent Cr species were responsible for the high activities of catalysts.