Combined Steam and Carbon Dioxide Reforming of Methane on Ni/MgAl₂O₄: Effect of CeO₂ Promoter to Catalytic Performance

Abstract

The catalytic performance during combined steam and carbon dioxide reforming of methane (SCR) was investigated on Ni/MgAl₂O₄ catalyst promoted with CeO₂. The SCR catalyst was prepared by co-impregnation method using nickel and cerium metal precursors on hydrotalcite-like MgAl₂O₄ support. In terms of catalytic activity and stability, CeO₂-promoted Ni/MgAl₂O₄ catalyst is superior to Ni–CeO₂/Al₂O₃ or Ni/MgAl₂O₄ catalysts because of high resistance to coke formation and suppressed aggregation of nickel particles. The role of CeO₂ on Ni/MgAl₂O₄ catalyst was elucidated by carrying out the various characterization methods in the viewpoint of the aggregation of nickel particles and metal-support interactions. The observed superior catalytic performance on CeO₂-promoted Ni/MgAl₂O₄ catalyst at the weight ratio of MgO/Al₂O₃ of 3/7 seems to be closely related to high dispersion and low aggregation of active metals due to their strong interaction with the MgAl₂O₄ support and the adjacent contact of Ni and CeO₂ species. The CeO₂ promoter also plays an important role to suppress particle aggregation by forming an appropriate interaction of NiO–CeO₂ as well as Ni–MgAl₂O₄ with the concomitant enhancement of mobile oxygen content.

Graphical Abstract

The catalytic performance during combined steam and carbon dioxide reforming of methane was investigated on Ni/MgAl₂O₄ catalyst promoted with CeO₂. In terms of catalytic activity and stability, CeO₂-promoted Ni/MgAl₂O₄ catalyst (b) is superior to Ni/MgAl₂O₄ catalyst (a) because of high resistance to coke formation and suppressed aggregation of nickel particles at the following reaction conditions; T = 850 °C, P = 1.0 MPa, CH₄/CO₂/H₂O/N₂ molar ratio of 3/1.2/3/3 and SV = 200,000 mL(CH₄)/g_cat/h.