scholarly journals Peculiarities Of The Electrochemical Behaviour Of Noble Metals In Some Low-Temperature Melts

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.


2012 ◽  
Vol 518-523 ◽  
pp. 860-863
Author(s):  
Yan Hong Zhao ◽  
Chun Mei Zhang ◽  
Ting Liu ◽  
Qiang Qiang Du ◽  
Sheng Liang ◽  
...  

Europium doped tantalum oxide (europium-Ta2O5) particles were synthesized with a low temperature hydrothermal method. The electrochemical behaviour of an europium-Ta2O5 film electrode in 0.1 mol dm-3KCl solution containing 5 mmol dm-3K3Fe(CN)6was investigated using cyclic voltgrammetry (CV). The CV results indicated that the europium-Ta2O5film electrode exhibited good stable and reversible electrochemistry properties. The electrochemical reaction of K3Fe(CN)6was a diffusion-controlling process on the europium-Ta2O5film electrode. The europium-Ta2O5particles might have potential applications in electrochemical fields.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 662 ◽  
Author(s):  
Teruaki Fuchigami ◽  
Ryosuke Kimata ◽  
Masaaki Haneda ◽  
Ken-ichi Kakimoto

Highly stable and active low-temperature CO oxidation catalysts without noble metals are desirable to achieve a sustainable society. While zero-dimensional to three-dimensional Co3O4 nanoparticles show high catalytic activity, simple-structured nanocrystals easily self-aggregate and become sintered during catalytic reaction. Thus, complex three-dimensional nanostructures with high stability are of considerable interest. However, the controlled synthesis of complex nanoscale shapes remains a great challenge as no synthesis theory has been established. In this study, 100 nm raspberry-shaped nanoparticles composed of 7–8 nm Co3O4 nanoparticles were synthesized by hydrothermally treating cobalt glycolate solution with sodium sulfate. Surface single nanometer-scale structures with large surface areas of 89 m2·g−1 and abundant oxygen vacancies were produced. The sulfate ions functioned as bridging ligands to promote self-assembly and suppress particle growth. The Co3O4 nano-raspberry was highly stable under catalytic tests at 350 °C and achieved nearly 100% CO conversion at room temperature. The addition of bridging ligands is an effective method to control the formation of complex but ordered three-dimensional nanostructures that possessed extreme thermal and chemical stability and exhibited high performance.


Author(s):  
Andrey S. Yasinskiy ◽  
Sai Krishna Padamata ◽  
Peter V. Polyakov ◽  
Aleksandr S. Samoilo ◽  
Andrey V. Suzdaltsev ◽  
...  

1970 ◽  
Vol 9 (9) ◽  
pp. 1045-1056 ◽  
Author(s):  
Kohji Yamakawa ◽  
Masakazu Nakao ◽  
F. Eiichi Fujita

2013 ◽  
Vol 320 ◽  
pp. 629-638 ◽  
Author(s):  
Yun Sang Feng ◽  
Shao Guang Liu ◽  
Cheng Wu Chen ◽  
He Yong Zhao ◽  
Yu Song Xu

Low-temperature SCR DeNOx process is considered to be a potential technique to meet the stringent environment regulations. It can avoid the problem such as blocking and eroding often generated in medium temperature, polluting and poisoning caused by alkali elements and so on. In this paper, a review of DeNOx catalysts about noble metals, molecular sieve, carbon-based and metal oxides catalyst was presented. The affecting factors of the low-temperature activation were comprehensively expounded, such as precursor introduction method, preparation method, supporter pretreatment and catalyst structure. Then mechanism of SO2 poisoning and effect of active compositions were analyzed. The dual effect of SO2 on the activity of low temperature catalysts mainly results from the formation of certain sulfur-containing species on catalyst surface. Water vapor decreased the number of available active sites attributed to competitive adsorption among H2O and other reactants. Moreover, the co-existence of H2O and SO2 resulted in the decrease of activity obviously. So the way to improve resistance of SO2 and H2O poisoning was summed up. Finally, future research and development directions in the developing low-temperature SCR for removal of NOx technology were proposed.


1991 ◽  
Vol 05 (18) ◽  
pp. 1191-1198 ◽  
Author(s):  
E. ILISCA

EELS experiments of H 2 absorbed at low temperature on Noble Metals have indicated that the o-p H 2 conversion can be very fast on metals, even in absence of chemisorption, in contradiction with the usual belief that the catalyst must be magnetic to be efficient. We examine a large family of processes which convert the hydrogen molecules on the basis of the emission of metal electron-hole pairs. The most efficient mechanism found is the Coulomb-Contact one based on a virtual charge transfer, back and forth, from the metal to the molecule, having a rate in agreement with experiment.


1979 ◽  
Vol 19 (12) ◽  
pp. 6260-6266 ◽  
Author(s):  
E. Borchi ◽  
S. De Gennaro ◽  
G. Pelosi ◽  
A. Rettori ◽  
P. L. Tasselli

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