Comparison of mono metallic and bimetallics Co, Ni catalysts supported on Al2O3/ZSM-5 for CO2 reforming of methane

Abstract

Carbon dioxide dry reforming of methane produces synthesis gas with variable ratio of hydrogen to carbon monoxide, which is desirable for industrial synthesis processes. This reaction also has much importance in environmental implications since both carbon dioxide and methane contribute to the greenhouse effect. Converting these gases into valuable feedstocks may reduce the atmospheric emission of CO2 and CH4. Firstly, the different loading order between 10%Co and 10%Ni metals on Al2O3/ZSM-5 was studied. Then, the good catalyst from part one was selected to be investigated in part part two. Secondly, the catalysts preparation with different molar ratios to obtain 10%Ni , 7.5%Ni 2.5%Co , 5%Ni 5%Co , 2.5%Ni 7.5%Co and 10%Co on Al2O3/ZSM-5 was investigated. Also, the monometallic and bimetallic were compared for CO2 reforming of methane. The Characterization of chemical and physical properties of catalysts by techniques of X-Ray Diffraction pattern (XRD), Nitrogen physorption, Scanning Electron Microscopy (SEM), NH3 Temperature Programmed Desorption (NH3-TPD), H2 Temperature programmed reduction (H2-TPR), Thermo gravimetric analyze (TGA), CO chemisorption was conducted. The CO2 reforming of methane was carried out at 700 oC with CO2:CH4 ratio of 50:50. The bimetallic catalysts (5%Ni 5%Co/Al2O3/ZSM-5) had high H2 selectivity of about 47% with low CO selectivity of about 53%, high H2 yield of about 34 %, high CO yield 78 %, high volume of CO adsorption, high active site, high metal dispersion and high stability despite relatively higher coke formation than the other catalysts.