Hydrogen production through CO2 reforming of methane over Ni/CeZrO2/Al2O3 catalysts

•Ni/CeZrO2 catalysts exhibited a higher OSC due to the formation of a ceria–zirconia solid solution.•Carbon deposition occurred over all catalysts.•Covering alumina with ceria–zirconia significantly decreased the amount of carbon deposited.•The higher oxygen mobility of the ceria–zirconia solid solution inhibited the formation of carbon.•The ceria zirconia improves the effectiveness of the carbon cleaning mechanism.

This work studied the performance of Ni/CexZr1−xO2/Al2O3 (x = 0.5; 0.75; 1.0) catalysts for the production of synthesis gas through CO2 reforming of CH4. Ni/Al2O3 and Ni/CeO2/Al2O3 catalysts exhibited an increase of methane and CO2 conversion at the beginning of reaction. For Ni/Ce0.75Zr0.25O2/Al2O3 and Ni/Ce0.50Zr0.50O2/Al2O3 catalysts, the conversion remained quite constant during the reaction. This result was associated with the oxidation of metallic Ni particles by CO2 from the feed. Ceria–zirconia support was preferentially oxidized, inhibiting the oxidation of the metallic phase. Carbon was formed over all catalysts. However, the amount of carbon deposits significantly decreased for Ni/Ce0.75Zr0.25O2/Al2O3 and Ni/Ce0.50Zr0.50O2/Al2O3 catalysts. This result was attributed to the high oxygen mobility of the homogeneous solid solution formed, which promoted the mechanism of carbon removal from the metallic particle.

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