標題: Ex-situ soft X-ray absorption spectroscopic investigation of NiCo2O4 annealed in different gases for hydrogen generation by electrolysis of urea
作者: Chang, Han-Wei
Dong, Chung-Li
Lu, Ying-Rui
Huang, Yu-Cheng
Chen, Chi-Liang
Chen, Jeng-Lung
Chen, Jin-Ming
Lee, Jyh-Fu
Tsai, Yu-Chen
加速器光源科技與應用學位學程
Master and Ph.D. Program for Science and Technology of Accelrrator Light Source
關鍵字: X-ray absorption spectroscopy;NiCo2O4;Electrocatalytic mechanism
公開日期: 14-Jun-2019
摘要: Electrochemical and ex-situ X-ray absorption spectroscopic (XAS) measurements of NiCo2O4 that have been annealed in different gases (Ar and air) were made to evaluate the efficiency of its electrocatalysis of hydrogen generation by the electrolysis of urea. The electrochemical and XAS measurements demonstrated that NCO-Ar contain significant amounts of Co2+ in octahedral coordination was more favorable than NCO-air for urea electrolysis owing to the effective exposure of electrochemical active sites to participate in the Faradic redox reaction. Further insight into the electrocatalytic mechanism of NiCo2O4-based materials during urea electrolysis was obtained using ex-situ soft XAS. The results of ex-situ soft XAS revealed that the variation of the octahedral and tetrahedral coordinations of Co2+ in NCO-Ar and NCO-air importantly contributes to electrocatalytic behavior. NCO-Ar exhibits excellent electrocatalytic activity towards the Co redox couples in a repetitive cycling process owing to the creation of highly efficient active sites (octahedral Co2+). This study presents importantly x-ray spectroscopic determination of the change in electronic structure of catalyst for hydrogen production. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.ijhydene.2018.10.108
http://hdl.handle.net/11536/152217
ISSN: 0360-3199
DOI: 10.1016/j.ijhydene.2018.10.108
期刊: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Volume: 44
Issue: 30
起始頁: 15771
結束頁: 15778
Appears in Collections:Articles