ZIF-8에서 유도된 니켈 단원자 촉매의 고효율 전기화학적 이산화탄소환원반응

Abstract

Carbon supported metal single atom catalysts (SACs) have received great attention due to their high activity and selectivity for carbon dioxide reduction reaction (CO2 RR). Various precursors of SACs are reported such as graphene, carbon nanofiber, carbon black, etc. Especially, metal-organic frameworks (MOFs) are effective for their beneficial effects: rich in nitrogen and porous carbon support. Meanwhile, it is well known that the doping on catalyst can bring both high selectivity and efficiency because the binding energy of key intermediates can be controlled by a charge transfer at the interface of dopant and catalyst. Recently, pyrolysis of Zeolitic Imidazolate Framework-8 (ZIF-8) shows great catalytic performance as CO2RR. However, there are few studies reported the effect of pyrolysis of MOF catalysts and no clear explanation on enhanced catalytic properties. Herein, we report an investigation of Ni single atom catalyst sites during the pyrolysis of ZIF-8 at temperatures ranging from 800 to 1000 degrees to enhanced catalytic performance. This single atom catalyst exhibited an excellent Faradaic efficiency (FE) under a wide potential range (>90% CO selectivity in the range of -0.5 to -1.4 V reversible hydrogen electrode), partial current density of -148.25 mA/cm2, and stability. N-moiety and carbon support are investigated by XPS and Ni K-edge investigated by XAS to develop property relationships. This study suggests that pyrolysis of ZIF-8 is key in the design of single atom catalytic application and its importance in mass production.