Influence of oxidative treatment of copper grid electrodes on the efficiency of conversion to aniline in the electroreduction of nitrobenzene and azobenzene in basic aqueous methanol

1994 ◽  
Vol 72 (12) ◽  
pp. 2353-2360 ◽  
Author(s):  
Anna Martel ◽  
Amoy Kam Cheong ◽  
Jean Lessard ◽  
Louis Brossard

The influence of preoxidizing the surface of polycrystalline copper electrodes on the efficiency of the controlled potential electrochemical reduction of nitrobenzene and azobenzene to aniline in basic aqueous methanol has been investigated. Electrodes electrochemically preoxidized to Cu(OH)2 or to Cu2O gave high yields of aniline (90–100%) with high current efficiencies (88–99%) for the electrohydrogenation of nitrobenzene compared to electrodes preoxidized by air (7–29% of aniline, 64–74% current efficiency). For the electrohydrogenation of azobenzene, copper electrodes preoxidized to Cu2O were found to be more active (average yield of aniline of 28%, average current efficiency of 55%) than electrodes preoxidized to Cu(OH)2 (3–11% of aniline, 42–53% current efficiency), and electrodes preoxidized by air were inactive (the electrohydrogenation stopped at hydrazobenzene). The improvement of activity induced by preoxidation of the copper surface is linked to the increase of the surface area.

2018 ◽  
Vol 165 (14) ◽  
pp. E768-E772
Author(s):  
Meng Shi ◽  
Shelly Li ◽  
Haiyan Zhao

2014 ◽  
Vol 294 ◽  
pp. 9-14 ◽  
Author(s):  
Zaiqiang Zhang ◽  
Shengzhi Yang ◽  
Peng Lv ◽  
Yan Li ◽  
Xiaotong Wang ◽  
...  

2012 ◽  
Vol 66 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Milorad Tomic ◽  
Miomir Pavlovic

The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2).


2018 ◽  
Vol 47 (22) ◽  
pp. 7587-7593 ◽  
Author(s):  
Ning Su ◽  
Zheng-Guang Wu ◽  
You-Xuan Zheng

Two efficient bluish green iridium(iii) complexes were applied as emitters in the organic light-emitting diodes, which showing high current efficiency of 58.17 cd A−1 and external quantum efficiency of 25.33% with low efficiency roll-off.


2019 ◽  
Vol 7 (37) ◽  
pp. 11569-11580 ◽  
Author(s):  
Athithan Maheshwaran ◽  
Vijaya Gopalan Sree ◽  
Ho-Yeol Park ◽  
Woosum Cho ◽  
Hyein Kim ◽  
...  

Highly efficient (D–π–A)-type host and green Ir(iii) complexes are introduced for solution-processed PHOLEDs that achieve high CE with considerably high EQE. The devices with symmetrical complex show more stable than those with asymmetrical complex.


2002 ◽  
Vol 2 ◽  
pp. 48-52 ◽  
Author(s):  
Zhirong Sun ◽  
Xiang Hu ◽  
Ding Zhou

Wastewater minimization in phenylacetaldehyde production by using indirect electrochemical oxidation of phenylethane instead of the seriously polluting traditional chemical process is described in this paper. Results show that high current efficiency of Mn(III) and high yield of phenylacetaldehyde can be obtained at the same sulfuric acid concentration (60%). The electrolytic mediator can be recycled and there will be no waste discharged.


Langmuir ◽  
2014 ◽  
Vol 30 (50) ◽  
pp. 15053-15056 ◽  
Author(s):  
Youn-Geun Kim ◽  
Jack Hess Baricuatro ◽  
Alnald Javier ◽  
John Mathew Gregoire ◽  
Manuel P. Soriaga

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