气候变化领域集成服务门户(CCPortal): Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting

CCPortal

DOI	10.1039/c8ee03282c
	Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting
	Qiu Z.; Tai C.-W.; Niklasson G.A.; Edvinsson T.
发表日期	2019
ISSN	17545692
起始页码	572
结束页码	581
卷号	12 期号:2
英文摘要	Earth-abundant transition metal-based compounds are of high interest as catalysts for sustainable hydrogen fuel generation. The realization of effective electrolysis of water, however, is still limited by the requirement of a high sustainable driving potential above thermodynamic requirements. Here, we report dynamically self-optimized (DSO) NiFe layered double hydroxide (LDH) nanosheets with promising bi-functional performance. Compared with pristine NiFe LDH, DSO NiFe LDH exhibits much lower overpotential for the hydrogen evolution reaction (HER), even outperforming platinum. Under 1 M KOH aqueous electrolyte, the bi-functional DSO catalysts show an overpotential of 184 and-59 mV without iR compensation for oxygen evolution reaction (OER) and HER at 10 mA cm -2 . The material system operates at 1.48 V and 1.29 V to reach 10 and 1 mA cm -2 in two-electrode measurements, corresponding to 83% and 95% electricity-to-fuel conversion efficiency with respect to the lower heating value of hydrogen. The material is seen to dynamically reform the active phase of the surface layer during HER and OER, where the pristine and activated catalysts are analyzed with ex situ XPS, SAED and EELS as well as with in situ Raman spectro-electrochemistry. The results show transformation into different active interfacial species during OER and HER, revealing a synergistic interplay between iron and nickel in facilitating water electrolysis. © 2019 The Royal Society of Chemistry.
英文关键词	Calorific value; Catalysts; Electrolysis; Electrolytes; Hydrogen; Potassium hydroxide; Transition metals; Aqueous electrolyte; Electrolysis of waters; Fuel conversion efficiencies; Hydrogen evolution reactions; Layered double hydroxides; Lower heating value; Oxygen evolution reaction; Transition-metal-based compounds; Iron alloys; alkaline water; catalyst; comparative study; electrokinesis; hydrolysis; hydroxide; optimization; performance assessment
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189986
作者单位	Department of Engineering Sciences, Solid State Physics, Uppsala University, Box 534, Uppsala, SE-75121, Sweden; Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, SE-10691, Sweden
推荐引用方式 GB/T 7714	Qiu Z.,Tai C.-W.,Niklasson G.A.,et al. Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting[J],2019,12(2).
APA	Qiu Z.,Tai C.-W.,Niklasson G.A.,&Edvinsson T..(2019).Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting.Energy & Environmental Science,12(2).
MLA	Qiu Z.,et al."Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting".Energy & Environmental Science 12.2(2019).