A sulfur-tolerant cathode catalyst fabricated with in situ exsolved CoNi alloy nanoparticles anchored on a Ruddlesden–Popper support for CO2 electrolysis. Issue 1 (14th October 2019)

• Record Type: Journal Article
• Authors: Park, Seongmin; Kim, Yoongon; Noh, Yuseong; Kim, Taewook; Han, Hyunsu; Yoon, Wongeun; Choi, Junil; Yi, Sang-Ho; Lee, Woon-Jae; Kim, Won Bae
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 1(2020)
• Page Start: 138
• Page End: 148
• Publication Date: 2019-10-14
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta07700f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The schematic of CO2 electrolysis to produce CO in an SOEC under the conditions of CO2 gas containing H2 S. Abstract : We developed a new and efficient sulfur-tolerant catalyst for application as a solid oxide electrolysis cell (SOEC) cathode designed with in situ exsolved CoNi alloy nanoparticles anchored on a Ruddlesden–Popper (R.P.) support of La1.2 Sr0.8 Co0.4 Mn0.6 O4 and evaluated its catalytic activity for CO2 electrolysis to CO under a CO2 gas stream containing H2 S species. This catalyst was prepared by in situ annealing of a perovskite derivative (La0.6 Sr0.4 Co0.5 Ni0.2 Mn0.3 O3 ) in a 20% H2 /N2 gas at 800 °C. The catalyst exhibited good reversibility of structural transitions during reduction and re-oxidation processes. A high current density of 703 mA cm −2 was achieved at 1.3 V and 850 °C with a maximum faradaic efficiency of 97.8%. In situ grown CoNi alloy nanoparticles and the high oxygen vacancy content in the R.P. support were responsible for its high catalytic activity and efficiency. Importantly, no sign of performance degradation was observed in galvanostatic tests over a period of 90 h operation under H2 S-containing CO2 gas conditions. Moreover, the catalyst showed no noticeable structural changes even after exposure to 100 ppm H2 S/N2, indicating that the catalyst developed in this study is highly active for CO2 electrolysis with a high tolerance against sulfur-poisoning species. Therefore, this Ruddlesden–Popper material with in situ exsolved CoNi alloy nanoparticles should be a promising cathode catalyst for practical application to H2 S-containing CO2 gas streams that are effluents of power stations or steel making plants.