Methane dry reforming reaction was investigated over Ir catalysts supported on ceria-based solid solutions. The doping of Pr6O11 or ZrO2 into the matrix of ceria yields more oxygen defects, resulting in an improved redox property and enhanced metal-support interaction in Ir/Ce0.9M0.1O2 (M = Pr, Zr) catalysts compared to Ir/CeO2 catalyst. The Ir/Ce0.9M0.1O2 (M= Pr, Zr) catalysts showed higher catalytic performance and better stability than the Ir/CeO2 catalyst, which were assigned to positive effects of doping in maintaining Ir nanoparticles, stabilizing catalyst structure, and the strong metal-support interaction in reducing carbon deposition. (C) 2016 Elsevier B.V. All rights reserved.