Highly Stable and Efficient Catalyst with In Situ Exsolved Fe–Ni Alloy Nanospheres Socketed on an Oxygen Deficient Perovskite for Direct CO2 Electrolysis

详细信息    查看全文

• 作者：Subiao Liu ; Qingxia Liu ; Jing-Li Luo
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：September 2, 2016
• 年：2016
• 卷：6
• 期：9
• 页码：6219-6228
• 全文大小：695K
• 年卷期：0
• ISSN：2155-5435

文摘

The massive emission of carbon dioxide (CO₂), the major portion of greenhouse gases, has negatively affected our ecosystem. Developing new technologies to effectively reduce CO₂ emission or convert CO₂ to useful products has never been more imperative. In response to this challenge, we herein developed novel in situ exsolved Fe–Ni alloy nanospheres uniformly socketed on an oxygen-deficient perovskite [La(Sr)Fe(Ni)] as a highly stable and efficient catalyst for the effective conversion of CO₂ to carbon monoxide (CO) in a high-temperature solid oxide electrolysis cell (HT-SOEC). The symmetry between the reduction and reoxidation cycles of this catalyst indicates its good redox reversibility. The cathodic reaction kinetics for CO₂ electrolysis is significantly improved with a polarization resistance as low as 0.272 Ω cm². In addition, a remarkably enhanced current density of 1.78 A cm^–2, along with a high Faraday efficiency (∼98.8%), was achieved at 1.6 V and 850 °C. Moreover, the potentiostatic stability test of up to 100 h showed that the cell was stable without any noticeable coking in a CO₂/CO (70:30) flow at an applied potential of 0.6 V (vs OCV) and 850 °C. The increased oxygen vacancies together with the in situ exsolved nanospheres on the perovskite backbone ensures sufficiently active sites and consequently improves the electrochemical performance for the efficient CO₂ conversion. Therefore, this newly developed perovskite can be a promising cathode material for HT-SOEC. More generally, this study points to a new direction to develop highly efficient catalysts in the form of the perovskite oxides with perfectly in situ exsolved metal/bimetal nanospheres.