Temperature-regulated reversible transformation of spinel-to-oxyhydroxide active species for electrocatalytic water oxidation

2020 ◽  
Vol 8 (4) ◽  
pp. 1631-1635 ◽  
Author(s):  
Tingli Zhou ◽  
Changhong Wang ◽  
Yanmei Shi ◽  
Yu Liang ◽  
Yifu Yu ◽  
...  

The active species of NiCo2O4 for OER is found to be NiCo2O4 at room temperature, and Ni(Co) oxyhydroxides at 45 °C. The alternate change of the reaction temperature induce reversible transformation between NiCo2O4 and Ni(Co) oxyhydroxides.

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Ros ◽  
C. Canals-Batlle ◽  
M.A. Lillo-Ródenas ◽  
E. Fuente ◽  
M. A. Montes-Morán ◽  
...  

This paper focuses on the valorisation of solid residues obtained from the thermal treatment of sewage sludge. In particular, sewage sludge samples were collected from two waste water treatment plants (WWTPs) with different sludge line basic operations. After drying, sludges were heated up to 700 °C in appropriate ovens under diluted air (gasification) and inert (pyrolysis) atmospheres. The solids obtained, as well as the dried (raw) sludges, were characterised to determine their textural properties and chemical composition, including the speciation of their inorganic fraction. All the materials under study were employed as adsorbents/catalysts in H2S removal experiments at room temperature. It was found that, depending on the particular sludge characteristics, outstanding results can be achieved both in terms of retention capacities and selectivity. Some of the solids outperform commercially available sorbents specially designed for gaseous emissions control. In these adsorbents/catalysts, H2S is selectively oxidised to elemental sulphur most likely due to the presence of inorganic, catalytically active species. The role of the carbon-enriched part on these solids is also remarked.


2021 ◽  
Author(s):  
Y. Popat ◽  
M. Orlandi ◽  
S. Gupta ◽  
N. Bazzanella ◽  
S. Pillai ◽  
...  

Abstract Mixed transition-metals oxide electrocatalysts have shown huge potential for electrochemical water oxidation due to their earth abundance, low cost and excellent electrocatalytic activity. Here we present Co–Fe–B–O coatings as oxygen evolution catalyst synthesized by Pulsed Laser Deposition (PLD) which provided flexibility to investigate the effect of morphology and structural transformation on the catalytic activity. As an unusual behaviour, nanomorphology of 3D-urchin-like particles assembled with crystallized CoFe2O4 nanowires, acquiring high surface area, displayed inferior performance as compared to core–shell particles with partially crystalline shell containing boron. The best electrochemical activity towards water oxidation in alkaline medium with an overpotential of 315 mV at 10 mA/cm2 along with a Tafel slope of 31.5 mV/dec was recorded with core–shell particle morphology. Systematic comparison with control samples highlighted the role of all the elements, with Co being the active element, boron prevents the complete oxidation of Co to form Co3+ active species (CoOOH), while Fe assists in reducing Co3+ to Co2+ so that these species are regenerated in the successive cycles. Thorough observation of results also indicates that the activity of the active sites play a dominating role in determining the performance of the electrocatalyst over the number of adsorption sites. The synthesized Co–Fe–B–O coatings displayed good stability and recyclability thereby showcasing potential for industrial applications. Graphic Abstract


2020 ◽  
Vol 10 (10) ◽  
pp. 3399-3408 ◽  
Author(s):  
Hussein A. Younus ◽  
Nazir Ahmad ◽  
Ibrahim Yildiz ◽  
Serge Zhuiykov ◽  
Shiguo Zhang ◽  
...  

Ligand transformations involved in metal complexes during water oxidation (WO), such as ligand decomposition, partial oxidation, or complete dissociation have been reported, however, ligand photodissociation has not been reported yet.


2014 ◽  
Vol 809-810 ◽  
pp. 493-499
Author(s):  
Li Fang Bao ◽  
Chen Li Wang ◽  
Jin Chuan Gu ◽  
Sheng Zhong ◽  
Rui Wang

The impact on the adsorption of Zn2+of these factors, initial concentration, modification time, reaction time vermiculite dosage, reaction temperature and pH having, and absorption mechanism are studied . The results show that: microwave modification time 30s, reaction time 40min, modified vermiculite dosage 8g/L, reaction temperature 30°C, reaction pH 6, Zn2+ adsorption rate can reach 97.91%, adsorption isotherms of Zn2+ by microwave modified vermiculite show that the adsorption equilibrium is consistent with Langmuir curves, correlation coefficient reached to 0.997 at room temperature.


2014 ◽  
Vol 17 (2) ◽  
Author(s):  
Ma Chao

AbstractSupercritical water oxidation (SCWO) of wastewater-based drilling fluid had been examined in a high-pressure reactor under the following conditions: reaction temperature, 520 °C to 580 °C; pressure, 26 MPa to 30 MPa; H


2018 ◽  
Vol 378 ◽  
pp. 353-361 ◽  
Author(s):  
Eric Allcorn ◽  
Ganesan Nagasubramanian ◽  
Harry D. Pratt ◽  
Erik Spoerke ◽  
David Ingersoll

RSC Advances ◽  
2017 ◽  
Vol 7 (52) ◽  
pp. 32923-32930 ◽  
Author(s):  
Yisu Yang ◽  
Linzhou Zhuang ◽  
Thomas E. Rufford ◽  
Shaobin Wang ◽  
Zhonghua Zhu

We present a variety of amorphous transition-metal borides prepared at room temperature by a chemical reduction method as highly active catalysts for the oxygen evolution reaction (OER).


RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 103088-103094 ◽  
Author(s):  
Jesús Sanmartín-Matalobos ◽  
Concepcion González-Bello ◽  
Lucía Briones-Miguéns ◽  
Matilde Fondo ◽  
Ana M. García-Deibe

The degradation under ambient humidity and room temperature of Pd(OAc)2(NEt3), which is an efficient catalyst for the aerobic oxidation of alcohols, to diethylamine and acetaldehyde derivatives is disclosed.


Sign in / Sign up

Export Citation Format

Share Document