Search results for "electrocatalyst"

CO2fixation and activation by metal complexes of small polyazacyclophanes

2001

The interaction of the cyclophanes 2,6,9,13-tetraaza[14]paracyclophane (L1) and 2,6,9,13-tetraaza[14]metacyclophane (L2) and of their Zn2+ and Cu2+ complexes with CO32− and its protonated forms is described. The actuation of the Cu2+–L2 system as an electrocatalyst for the reduction of CO2 to CO in water is advanced. Copyright © 2001 John Wiley & Sons, Ltd.

Cobalt(IV) corroles as catalysts for the electroreduction of O2: reactions of heterobimetallic dyads containing a face-to-face linked Fe(III) or Mn(I…

2006

Abstract A series of heterobinuclear cofacial porphyrin–corrole dyads containing a Co(IV) corrole linked by one of four different spacers in a face-to-face arrangement with an Fe(III) or Mn(III) porphyrin have been examined as catalysts for the electroreduction of O 2 to H 2 O and/or H 2 O 2 when adsorbed on the surface of a graphite electrode in air-saturated aqueous solutions containing 1 M HClO 4 . The examined compounds are represented as (PCY)M III ClCo IV Cl where P is a porphyrin dianion, C is a corrole trianion and Y is a biphenylene (B), 9,9-dimethylxanthene (X), dibenzofuran (O) or anthracene (A) spacer. The catalytic behavior of the seven investigated dyads in the two heterobimet…

Elucidation of Pathways for NO Electroreduction on Pt(111) from First Principles

2015

The mechanism of nitric oxide electroreduction on Pt(111) is investigated using a combination of first principles calculations and electrokinetic rate theories. Barriers for chemical cleavage of N-O bonds on Pt(111) are found to be inaccessibly high at room temperature, implying that explicit electrochemical steps, along with the aqueous environment, play important roles in the experimentally observed formation of ammonia. Use of explicit water models, and associated determination of potential-dependent barriers based on Bulter-Volmer kinetics, demonstrate that ammonia is produced through a series of water-assisted protonation and bond dissociation steps at modest voltages (0.3 V). In addit…

Oxygen evolution reaction on a N-doped Co0.5-terminated Co3O4 (001) surface

2020

The project AP05131211 “First principles investigation on catalytic properties of N-doped Co3O4.” was funded by the Ministry of Education and Science of the Republic of Kazakhstan. The work was partly supported by COST (European Cooperation in science and Technology) Action 18234 (YM and EK). The work of T. Inerbaev was performed under the state assignment of Sobolev Institute of Geology and Mineralogy Siberian Branch of the Russian Academy of Sciences. YM and EK thank Sun-to-Chem project of ERA Net.

Uniform nanoporous graphene sponge from natural polysaccharides as a metal-free electrocatalyst for hydrogen generation

2019

[EN] Structuring of graphene as graphene sponges in the submicrometric scale has been achieved by using silica spheres (80 nm diameter) as hard templates and chitosan or alginate as precursor of defective N-doped or undoped graphene, respectively. The resulting defective N-doped graphene sponge exhibits a remarkable activity and stability for hydrogen evolution reaction with onset at 203 mV for a current density of 0.5 mA cm(-2) with a small Tafel plot slope of 69.7 mV dec(-1). In addition, the graphene sponge also exhibits a high double layer capacitance of 11.65 mF cm(-2). Comparison with an analogous N-doped graphene sample shows that this electrochemical properties derive from the spati…

Formation of ZnO nanowires by anodization under hydrodynamic conditions for photoelectrochemical water splitting

2020

[EN] The present work studies the influence of hydrodynamic conditions (from 0 to 5000 rpm) during Zn anodization process on the morphology, structure and photoelectrocatalytic behavior of ZnO nanostructures. For this purpose, analysis with Confocal Laser-Raman Spectroscopy, Field Emission Scanning Electron Microscope (FE-SEM) and photoelectrochemical water splitting tests were performed. This investigation reveals that hydrodynamic conditions during anodization promoted the formation of ordered ZnO nanowires along the surface that greatly enhance its stability and increases the photocurrent density response for water splitting in a 159% at the 5000 rpm electrode rotation speed.

Self-templated synthesis of novel carbon nanoarchitectures for efficient electrocatalysis

2016

AbstractThe cost-efficient large-scale production of novel carbon nanostructure with high performance is still a challenge, restricting their applications in catalysis. Herein, we present a low-cost one-pot and one-step approach for the synthesis of both N-doped graphene (NG) and N-doped carbon nanotubes (NCNTs) from self-templated organic nanoplates. By varying the FeCl3 concentration in the precursor, we can control the formation of graphene or CNTs. To the best of our knowledge, this is the first example for the controllable synthesis of graphene or CNTs by varying the precursors’ compositions. This provides a simple and cost-effective route for the large-scale production of both NG and …

Ni alloy nanowires as high efficiency electrode materialsnfor alkaline electrolysers

2020

Hydrogen production by water electrolysis (WE) is a very promising technology because it is a pollution-free process especially if renewable sources are employed to energy supply. Nowadays, the cost of hydrogen production by WE is higher than other available technologies, which makes WE not competitive. Many efforts have been made to improve WE performance, through the use of electrodes made of transition metal alloys as cathode and compound of metal oxide as anode [1]. In the field of water-alkaline electrolyzer, the development of cheap nanoporous based nickel electrodes with high electrocatalytic features is one of the potential approaches to increase the WE performance [2]. A facile met…

Constant potential rate theory – general formulation and electrocatalysis

2021

A Comparative Study of Poly(Azure A) Film-Modified Disposable Electrodes for Electrocatalytic Oxidation of H₂O₂: Effect of Doping Anion.

2018

In the present paper, poly(azure A) (PAA) films were electrosynthetized in the presence of different doping anions on disposable screen-printed carbon electrodes (SPCEs). The anions used included inorganic monoatomic (chloride and fluoride), inorganic polyatomic (nitrate and sulfate) and organic polyatomic (dodecyl sulfate, DS) species. The coated electrodes thus obtained were characterized by electrochemical techniques and SEM. They showed improved electrocatalytic activities towards hydrogen peroxide oxidation compared to that of a bare SPCE. In particular, the insertion of DS anions inside PAA films provided a special sensitivity to the electrocatalysis of H2O2, which endowed these elect…