Effect of cobalt on the activity of nickel-based/magnesium-substituted hydroxyapatite catalysts for dry reforming of methane

Abstract

The dry reforming of methane (DRM) reaction can directly convert methane (CH₄) and carbon dioxide (CO₂) into syngas (H₂+CO), which is a promising method for achieving carbon neutralization. In this study, a series of 3Ni-xCo/Mg₁HAP alloy catalysts with different ratio were synthesized by the coprecipitation method, and the optimum Ni–Co ratio for the DRM reaction was studied. A series of characterization methods revealed that after Co was added, the formation of Ni–Co alloys increased the interactions between metals. However, an excess of Co inhibits the entry of Ni into the lattice of Mg₁HAP, resulting in metal accumulation on the surface of the support. In addition, the introduction of Co improves the dispersion of Ni metal, which endows the catalyst with better catalytic activity and stability. Raman spectroscopy of the catalyst after the stability test showed that the addition of Co reduced the proportion of graphitic carbon, which was also the main reason for its improved stability.