纳米颗粒
化学
电化学
催化作用
选择性
法拉第效率
电解质
偶联反应
化学工程
氧化还原
无机化学
纳米技术
电极
物理化学
材料科学
有机化学
工程类
作者
Hee-Suk Jung,Si Young Lee,Chan Woo Lee,Min Kyung Cho,Da Hye Won,Cheonghee Kim,Hyung Suk Oh,Byoung Koun Min,Yun Jeong Hwang
摘要
In this study, we demonstrate that the initial morphology of nanoparticles can be transformed into small fragmented nanoparticles, which were densely contacted to each other, during electrochemical CO2 reduction reaction (CO2RR). Cu-based nanoparticles were directly grown on a carbon support by using cysteamine immobilization agent, and the synthesized nanoparticle catalyst showed increasing activity during initial CO2RR, doubling Faradaic efficiency of C2H4 production from 27% to 57.3%. The increased C2H4 production activity was related to the morphological transformation over reaction time. Twenty nm cubic Cu2O crystalline particles gradually experienced in situ electrochemical fragmentation into 2–4 nm small particles under the negative potential, and the fragmentation was found to be initiated from the surface of the nanocrystal. Compared to Cu@CuO nanoparticle/C or bulk Cu foil, the fragmented Cu-based NP/C catalyst achieved enhanced C2+ production selectivity, accounting 87% of the total CO2RR products, and suppressed H2 production. In-situ X-ray absorption near edge structure studies showed metallic Cu0 state was observed under CO2RR, but the fragmented nanoparticles were more readily reoxidized at open circuit potential inside of the electrolyte, allowing labile Cu states. The unique morphology, small nanoparticles stacked upon on another, is proposed to promote C–C coupling reaction selectivity from CO2RR by suppressing HER.
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