Electrochemical CO 2 Reduction on Bimetallic Surface Alloys: Enhanced Selectivity to CO for Co/Au(110) and to H 2 for Sn/Au(110)

2019 ◽  
Vol 6 (12) ◽  
pp. 3101-3107 ◽  
Author(s):  
Naoto Todoroki ◽  
Hiroki Tei ◽  
Taku Miyakawa ◽  
Hiroto Tsurumaki ◽  
Toshimasa Wadayama
2019 ◽  
Vol 7 (24) ◽  
pp. 19453-19462 ◽  
Author(s):  
Venkata Sai Sriram Mosali ◽  
Xiaolong Zhang ◽  
Ying Zhang ◽  
Thomas Gengenbach ◽  
Si-Xuan Guo ◽  
...  

2021 ◽  
Author(s):  
David Mahlberg ◽  
Sung Sakong ◽  
Axel Gross

Bimetallic surfaces allow tailoring their catalytic activity by modifying their composition and/or structure. However, under operating conditions, catalytically active bimetallic structures are often not stable and change their morphology which might reduce their functionality. Still, catalytically active structures do not necessarily need to be thermodynamically stable and might also be kinetically stabilized. Here we report kinetic Monte Carlo simulations based on density functional theory calculation to address the meta-stability of surface alloy systems. As structural changes can typically only occur via vacancy diffusion in the surface, we first determine the vacancy diffusion barrier as a function of their bimetallic environment. By determining the temporal evolution of the bimetallic surface alloys as a function of temperature, we analyze the factors underlying the stability and structure of the bimetallic surface alloys.


Author(s):  
Maximiliano Ramos ◽  
M. Natalia Batista ◽  
Alejandra E. Martínez ◽  
H. Fabio Busnengo

2020 ◽  
Vol 43 ◽  
pp. 154-160 ◽  
Author(s):  
Xianglong Lu ◽  
Tianshui Yu ◽  
Hailing Wang ◽  
Lihua Qian ◽  
Ruichun Luo ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1246
Author(s):  
Stefan Valkov ◽  
Dimitar Dechev ◽  
Nikolay Ivanov ◽  
Ruslan Bezdushnyi ◽  
Maria Ormanova ◽  
...  

In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.


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