The Preparation Of Perovskite-type High Temperature Proton Conductor And Its Application In Electrochemical Synthesis Of Ammonia

The industry of synthesis ammonia is most important to the development of our society. The traditional method of ammonia synthesis is Harber way which limited its further development. So, many novelty methods of ammonia synthesis were explored in recent years. It is one reasonable way of the methods that synthesis ammonia using high-temperature proton conductors(HTPC). A lot of research works have been done since the high temperature proton conductor was reported in 1980's,such as: conduction mechanism, structure, related electrical characterization, application research, etc. The potential application value of HTPC in gas sensors, SOFCs(solid oxide fuel cells) and gas separators is attributed to its high proton conduction ranges at high temperature under atmosphere containing hydrogen. While, the synthesis of ammonia using HTPC under atmosphere reported by George Marnellos and Michael Stoukides makes its perspective of application more practical and even more charming. We synthesized three series perovskite-type compounds using citrate sol-gel method which are one style of HTPC in this paper. BaCe_0.90Y_0.10O3-δ BaCeO₃ 基: BaCe_0.8Gd_0.2O3-δ BaCe_0.90Sm_0.10O3-δ Ba_0.90La_0.10Ce_0.90Y_0.10O_3-δ BaCe_0.80Gd_0.10Sm_0.10O3-δ Simple perovskite-type BaZrO3 type: BaCe0.2Zr0.7Y0.1O3-δBaZr0.9Y0.1O3-δ Ba3CaZr0.5Nb1.5O9-δComplex perovskite-type BCN18 type: Ba3(Ca1.18Nb1.82)O9-δ Ba3Ca0.9Nd0.28Nb1.82O9-δ We use thermal analysis (TG-DTA) to obtain the optimum calcination temperature of thermal decomposition. A single perovskite-type phase was confirmed by powder X-ray diffraction (XRD). The topography was characterized with transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Parameters such as working temperatures, different gas ambiences were changed to characterize the electrical properties of HTPC sinters prepared. All of the samples produce ammonia at different degrees, and the rates of ammonia formation are up to 10-9 mol.s-1.cm-2. And we also analyzed the effection of synthesing temperature and potential to the rate of ammonia formation. The result shows that we got larger specific surface of the samples using citrate sol-gel method comparison to the traditional solid reaction method, at the same time, the samples shoes the better sinter property and proton conduction property. During the experiment of synthesizing ammonia using different series HTPC, we found that the ability of synthesizing ammonia of each series HTPC were listed below: BaCeO3 type > BaZrO3 type > BCN18 type What is more, to the same series HTPC, double doped samples showed better...