Abstract: High temperature proton conductors were widely studied , because of their using in fuel cell , hydrogen separation membrane and hydrogen sensor , etc.In this paper, In and Gd co-doped BaCeO3 proton conductors were prepared by modified citrate method .The microstructure , chemical stability and electrical conductivity were further studied .The results show that the basicity of the system is improved after doping due to the low electronegativity of Gd , which leads to poor chemical stability .However , the ion radius of Gd is smaller than that of Ce , which is more favorable for ion transportation .Therefore , Gd single-doping and In , Gd co-doping samples have higher conductivity than traditional proton conductor samples.

Key words: High temperature proton conductors were widely studied , because of their using in fuel cell , hydrogen separation membrane and hydrogen sensor , etc.In this paper, In and Gd co-doped BaCeO3 proton conductors were prepared by modified citrate method .The microstructure , chemical stability and electrical conductivity were further studied .The results show that the basicity of the system is improved after doping due to the low electronegativity of Gd , which leads to poor chemical stability .However , the ion radius of Gd is smaller than that of Ce , which is more favorable for ion transportation .Therefore , Gd single-doping and In , Gd co-doping samples have higher conductivity than traditional proton conductor samples.