核壳结构Au@CeO催化剂上氨的环境电合成：CeO中氧空位的作用
Ambient Electrosynthesis of Ammonia on a Core-Shell-Structured Au@CeO Catalyst: Contribution of Oxygen Vacancies in CeO.
作者信息
Liu Guoqiang, Cui Zhiqing, Han Miaomiao, Zhang Shengbo, Zhao Cuijiao, Chen Chun, Wang Guozhong, Zhang Haimin
机构信息
Key Laboratory of Materials Physics, Centre for, Environmental and Energy Nanomaterials, Anhui Key Laboratory of, Nanomaterials and Nanostructures, CAS Center for Excellence in, Nanoscience, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, P.R. China.
University of Science and Technology of China, Hefei, 230026, P.R. China.
出版信息
Chemistry. 2019 Apr 23;25(23):5904-5911. doi: 10.1002/chem.201806377. Epub 2019 Mar 22.
Electrosynthesis of NH through the N reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy- and capital-intensive Haber-Bosch process. Herein, a room-temperature spontaneous redox approach to fabricate a core-shell-structured Au@CeO composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as-synthesized Au@CeO possesses a surface area of 40.7 m g and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH yield rate of 28.2 μg h cm (10.6 μg h mg , 293.8 μg h mg ) and a faradaic efficiency of 9.50 % at -0.4 V versus a reversible hydrogen electrode in 0.01 m H SO electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO nanoparticle shell of Au@CeO ; these are favorable for N adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO nanoparticle shell, combined with the Au nanoparticle core of Au@CeO , are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N into NH .
在环境条件下通过氮还原反应（NRR）电合成氨被认为是一种有前景的技术，有望取代工业上能源和资本密集型的哈伯-博施工艺。在此，报道了一种室温自发氧化还原方法，用于制备核壳结构的Au@CeO复合材料，其金纳米颗粒尺寸小于约10 nm，负载量为3.6 wt %，用于NRR。结果表明，合成的Au@CeO具有40.7 m g的表面积和多孔结构。作为电催化剂，它表现出高NRR活性，在0.01 m H SO电解液中，相对于可逆氢电极在-0.4 V时，氨产率为28.2 μg h cm（10.6 μg h mg ，293.8 μg h mg ），法拉第效率为9.50 %。表征结果表明，Au@CeO的CeO纳米颗粒壳层中存在丰富的氧空位；这些空位有利于NRR中氮的吸附和活化。这已通过理论计算得到进一步验证。CeO纳米颗粒壳层中丰富的氧空位与Au@CeO的金纳米颗粒核相结合，是NRR的电催化活性位点，因此协同增强了氮向氨的转化。
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