Performance Improvement And Application Of Perovskite Proton Conductor

Barium hafnium oxide matrix sub-conductor is a relatively novel solid electrolyte material with good electrical properties and chemical stability,and has broad application prospects.A single-phase and two dual-phase barium hafnate matrix proton-electron conductors were successfully prepared by solid-phase method,and their sintering properties,electrochemical properties and chemical stability properties were explored.And prepared into a proton-electron mixed conductor hydrogen permeable membrane to explore its hydrogen permeable performance.The BaHf_0.8-xMn_xIn_0.2O_3-δ（x=0.05,0.075,0.10,0.15,0.20）proton conductor was prepared by high temperature solid phase method,and the influence of Mn doping on the phase composition,microscopic morphology and electrical properties of BaHf O3 was studied.Studies have shown that when the doping ratio of Mn reaches 0.20,the second phase Mn O2 appears.The grain size increases as the doping ratio of Mn increases.With the increase of Mn doping,the conductivity of the sample gradually increased.At 700℃,the conductivity of the BaHf0.65Mn0.15In0.2O3-δsample in humid air is 7.26×10^-3 S·cm^-1.It is made into a hydrogen permeable membrane with a thickness of 1.13 mm,and the hydrogen permeation rate is 0.0369 m L·min^-1·cm^-2 at a temperature of 900℃ and a gas distribution of 50%H2/He.The amount of hydrogen permeation gradually increases with the increase of temperature and H2 concentration in the intake air.After passing water vapor into the raw gas or purge gas,the hydrogen permeation rate also increases.Two-phase proton-electron mixed conductors（8:2,7:3,6:4）with different molar ratios of BaHf_0.65Mn_0.15In_0.2O_3-δ-MnO₂ were prepared by high temperature solid phase method.Studies have shown that the sample is composed of two phases,and each element is evenly distributed in the sample.BaHf0.65Mn0.15In0.2O3-δ-Mn O2 has good chemical stability in H2O,5%H2/Ar,CO2,H2S atmosphere.The electrical conductivity was tested by the four-electrode method,and the results showed that the electrical conductivity increased with the increase of the electronic conductivity ratio,and the molar ratio of the sample was 6:4.The conductivity of the sample can reach 1.01×10^-1S·cm^-1 at 700℃ in the air.Two-phase proton-electron mixed conductors with different mass ratios（9:1,8:2,7:3）of BaHf_0.8In_0.2O_3-δ-BaFeO₃ were prepared by high temperature solid phase method.Studies have shown that the sample is composed of two-phase uniformly distributed.The BaHf0.8In0.2O3-δ-Ba Fe O3 dual-phase proton-electron mixed conductor with a mass ratio of7:3 has the highest conductivity,that is,the conductivity at 700℃ in the air is 3.09×10^-1S·cm^-1.Figure 46;Table 3;Reference 80...