Hydrogen production via CO2 reforming of methane over ZrO2-Doped Ni/ZSM-5 nanostructured catalyst prepared by ultrasound assisted sequential impregnation method

In our continuing effort to find the proper catalyst for CO2 reforming of methane, Ni(8%)/ZSM-5-ZrO2 with various zirconium loadings (0-15%) are synthesized via sonochemical method. All samples are characterized by XRD, FESEM, TEM, EDX, BET, FTIR and TPR-H-2 techniques. The XRD results confirm existence of NiO, ZrO2 and ZSM-5 as crystalline phase in catalyst structure. FESEM images reveal small particle size of active metals and low numbers of agglomerations for Ni(8%)/ZrO2(5%)-ZSM-5. BET analysis shows that addition of ZrO2 to Ni/ZSM-5 decreases the surface area but Ni/ZrO2(5%)-ZSM-5 has the highest surface area. TEM analysis demonstrates high dispersion of Ni nano particles over the support. EDX depicts the best active metal dispersion for the catalyst with 5% zirconia loading. The TPR results prove that the metal-support interaction is enhanced by zirconia addition, indicating the better Ni dispersion. Apart from characterization, activity tests are performed and parameters such as effect of temperature, CO and H-2 yields and H-2/CO ratio are investigated. The results show that Ni(8%)/ZrO2(5%)-ZSM-5 has the best structural properties and the highest activity and stability in comparison with the other catalysts. (C) 2014 Elsevier B.V. All rights reserved.