Influences of doping Cr/Fe/Ta on the performance of Ni/CeO₂ catalyst under microwave irradiation in dry reforming of CH₄

The structure of Ni/CeO₂ catalyst with doping of Cr, Fe and Ta was investigated with XRD, N₂ physisorption, XPS and HRTEM and the catalytic activity of the catalysts under microwave irradiation in dry reforming of methane was tested in a microwave reactor. The results show that the introduction of Cr and Ta to Ni/CeO₂ can enhance the interaction between Ni and the support/promoter and inhibit the enlargement of NiO particles during the synthesis. The CH₄ conversions in dry reforming on the catalysts follow the order: Ni/CeO₂<2Fe–Ni<2Ta–Ni<2Cr–Ni. The superior performance of 2Ta–Ni and 2Cr–Ni may be attributed to the locally-heated Ni particles caused by the strong microwave absorption of the in-situ grown graphene attached on them under microwave irradiation. - Highlights: • The influences of doping Cr, Fe and Ta on Ni/CeO₂ were investigated. • The catalytic performances before and after doping were investigated. • The in-situ grown graphene can promote the conversion of reactants.