scholarly journals Unravelling Composition–Activity–Stability Trends in High Entropy Alloy Electrocatalysts by Using a Data‐Guided Combinatorial Synthesis Strategy and Computational Modeling

2022 ◽  
pp. 2103312
Author(s):  
Lars Banko ◽  
Olga A. Krysiak ◽  
Jack K. Pedersen ◽  
Bin Xiao ◽  
Alan Savan ◽  
...  
2020 ◽  
Author(s):  
Hongdong Li ◽  
Yi Han ◽  
Huan Zhao ◽  
Wenjing Qi ◽  
Dan Zhang ◽  
...  

Abstract Designing electrocatalysts with high-performance for both reduction and oxidation reactions faces severe challenges. Here, the uniform and small size (~3.4 nm) high-entropy alloys (HEAs) Pt18Ni26Fe15Co14Cu27 nanoparticles (NPs) are synthesized by a simple low-temperature (<250 oC) oil phase synthesis strategy at atmospheric pressure for the first time. The Pt18Ni26Fe15Co14Cu27/C catalyst exhibits excellent electrocatalytic performance for hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The catalyst is one of the best performance achieved by state-of-the-art alkaline HER catalysts, which shows an ultrasmall overpotential of 11 mV at the current density of 10 mA cm-2, excellent activity (10.96 A mg-1Pt at -0.07 V vs. reversible hydrogen electrode) and stability in the alkaline medium. Furthermore, it is also the most efficient catalyst (15.04 A mg-1Pt) ever reported for MOR in alkaline solution. DFT calculations confirm the multi-active sites for both HER and MOR on the HEA surface as the key factor for both proton and intermediate transformation. Meanwhile, the construction of HEA surfaces supplies the fast site-to-site electron transfer for both reduction and oxidation processes.


Author(s):  
Dan Zhang ◽  
Yue Shi ◽  
Huan Zhao ◽  
Wenjing Qi ◽  
Xilei Chen ◽  
...  

Although intensive efforts have been made and great progress has been achieved relating to the electrocatalytic hydrogen evolution reaction (HER), an advanced synthesis strategy for an efficient electrocatalyst is still the most significant goal.


2020 ◽  
Author(s):  
Zhigang Zou ◽  
Bing Wang ◽  
Cheng Wang ◽  
Xiwen Yu ◽  
Yuan Cao ◽  
...  

Abstract High-entropy materials (HEMs) including high-entropy alloys (HEAs) and high-entropy ceramics (HECs) at nanoscale have promising prospects in many fields, yet a robust synthesis strategy is lacking. Herein, we present a simple and general approach, laser scanning ablation (LSA), to synthesize a vast library of HEA and HEC nanoparticles (NPs) including alloys, sulfides, oxides, borides, nitrides, phosphides. The LSA method takes only 5 nanoseconds per pulse to ablate the corresponding NPs precursors at atmospheric temperature and pressure in alkanes. The ultra-rapid process ensures up to 9 dissimilar metallic elements combined uniformly regardless of their thermodynamic solubility. As laser pulse precisely confines energy to desired microregions, the LSA method enables HEM NPs loading on various substrates, even thermally-sensitive ones such as metals and glass. Applied as electrocatalysts for overall water splitting, HEM NPs achieved an overpotential of 185 mV @ 10mA cm-2, which was among the best activities. The LSA technique discloses a large collection of new nanostructured HEMs with unique properties and attractive functions. We believe this general strategy will provide a versatile and flexible material platform for a wild range of fields such as biology, catalysis, electronics and magnetics.


2019 ◽  
Author(s):  
Nirmal Kumar ◽  
Subramanian Nellaiappan ◽  
Ritesh Kumar ◽  
Kirtiman Deo Malviya ◽  
K. G. Pradeep ◽  
...  

<div>Renewable harvesting clean and hydrogen energy using the benefits of novel multicatalytic materials of high entropy alloy (HEA equimolar Cu-Ag-Au-Pt-Pd) from formic acid with minimum energy input has been achieved in the present investigation. The synthesis effect of pristine elements in the HEA drives the electro-oxidation reaction towards non-carbonaceous pathway . The atomistic simulation based on DFT rationalize the distinct lowering of the d-band center for the individual atoms in the HEA as compared to the pristine counterparts. This catalytic activity of the HEA has also been extended to methanol electro-oxidation to show the unique capability of the novel catalyst. The nanostructured HEA, properties using a combination of casting and cry omilling techniques can further be utilized as fuel cell anode in direct formic acid/methanol fuel cells (DFFE).<br></div>


Author(s):  
Janez Dolinšek ◽  
Stanislav Vrtnik ◽  
J. Lužnik ◽  
P. Koželj ◽  
M. Feuerbacher

2006 ◽  
Vol 31 (6) ◽  
pp. 723-736 ◽  
Author(s):  
Keng-Hao Cheng ◽  
Chia-Han Lai ◽  
Su-Jien Lin ◽  
Jien-Wei Yeh

2019 ◽  
Author(s):  
Dong Geun Kim ◽  
Yong Hee Jo ◽  
Junha Yang ◽  
Won-Mi Choi ◽  
Hyoung Seop Kim ◽  
...  

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