Preparation and characterization of Ir Pt1−O2 anode electrocatalysts for the oxygen evolution reaction

Papazisi, Kalliopi-Maria; Siokou, A.; Balomenou, Stella; Tsiplakides, D.

doi:10.1016/j.ijhydene.2012.02.118

Cited by 30 publications

(24 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These non-noble metal oxides however do not show any catalytic activity for oxygen evolution reaction (OER) in PEM electrolysis conditions and at the same time exhibit very poor electronic conductivity which is a major detriment to achieving the desired optimal charge transport kinetics. It has been reported [10][11][12][13][14][15][16][17][18][19][20] reduce the noble metal loading while facilitating the achievement of high electronic conductivity and catalytic activity though reports have identified that there is a limiting concentration of diluents and support structures beyond which the active surface area, electrical conductivity and electrochemical activity decrease [11,14,[16][17][18][19][21][22][23][24][25][26][27]. Work from the present group of authors has demonstrated thin film solid solutions of F doped metal oxide (M x O y :F, M=Sn, Nb, Ta) containing low amount of IrO 2 or RuO 2 (~20 at.%) such as (Sn,Ir)O 2 :F, (Sn,Ru)O 2 :F, and (Ta,Ir)O 2 :F with electrochemical performance comparable to that of pure IrO 2 electrocatalyst [28][29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Kadakia

Jampani

Velikokhatnyi

et al. 2016

Materials Science and Engineering: B

View full text Add to dashboard Cite

High surface area (~300 m 2 /g) nanostructured powders of (Nb 1-x Ir x)O 2 and (Nb 1-x Ir x)O :10F (~100 m 2 /g) have been examined as promising oxygen evolution reaction (OER) electrocatalysts for proton exchange membrane (PEM) based water electrolysis. Nb 2 O 5 and 10 wt.% F doped Nb 2 O 5 powders were prepared by a low temperature sol-gel process which were then converted to solid solution (Nb,Ir)O 2 and 10 wt.% F doped (Nb,Ir)O 2 [(NbIr)O 2 :10F] electrocatalysts by soaking in IrCl 4 followed by heat treatment in air. Electro-catalyst powders of optimal composition (Nb 0.75 Ir 0.25)O 2 :10F with ~75 at.% reduction in noble metal content exhibited comparable OER activity to commercial hydrated IrO 2 and nanostructured in-house chemically synthesized IrO 2. The (Nb,Ir)O 2 :10F electro-catalyst demonstrated excellent long term structural/corrosion stability comparable to in-house chemically synthesized pure IrO 2 :10F. First-principles calculations of the total energies, electronic structures and cohesive energies of the model systems have been performed and correlated to the excellent activity, long term stability of (Nb,Ir)O 2 :F for OER obtained experimentally.

show abstract

Section: Introductionmentioning

confidence: 99%

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Kadakia

Jampani

Velikokhatnyi

et al. 2016

Materials Science and Engineering: B

View full text Add to dashboard Cite

show abstract

“…Decrease in the noble metal oxide (IrO 2 /RuO 2 ) loading with improved catalytic activity would enable much reduction in capital costs of PEM electrolyzer cells. It has been reported previously by many researchers [16][17][18][19][20][21][22][23][24][25][26][27] that addition of cheaper metal oxides or diluents (viz., SnO 2 , Ta 2 O 5 , TiO 2 , Nb 2 O 5 ) to the parent noble metal oxide resulting in a binary or ternary metal oxide mixture could reduce the overall noble metal oxide content. However, with the addition of the cheaper diluents results in a reduction in the active surface area and electronic conductivity of the mixed oxides [17,18,24,[28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Nanostructured F doped IrO2 electro-catalyst powders for PEM based water electrolysis

Kadakia

Jampani

Velikokhatnyi

et al. 2014

Journal of Power Sources

View full text Add to dashboard Cite

Fluorine doped iridium oxide (IrO 2 :F) powders with varying F content ranging from 0 to 20 wt.% has been synthesized by using a modification of the Adams fusion method. The precursors (IrCl 4 and NH 4 F) are mixed with NaNO 3 and heated to elevated temperatures to form high surface area nanomaterials as electro-catalysts for PEM based water electrolysis. The catalysts were then coated on a porous Ti substrate and have been studied for the oxygen evolution reaction in PEM based water electrolysis. The IrO 2 :F with an optimum composition of IrO 2 :10 wt.% F shows remarkably superior electrochemical activity and chemical stability compared to pure IrO 2. The results have also been supported via kinetic studies by conducting rotating disk electrode (RDE) experiments. The RDE studies confirm that the electro-catalysts follow the two electron transfer reaction for electrolysis with calculated activation energy of ~25kJ/mol. Single full cell tests conducted also validate the superior electrochemical activity of the 10 wt.% F doped IrO 2 .

show abstract

“…[12][13][14][15][16][17][18][19] , assuming standard conditions. They are thus reaction free energies and can be expressed as…”

Section: Introductionmentioning

confidence: 99%

H₂ production through electro-oxidation of SO₂: identifying the fundamental limitations

Kriek

Siahrostami

Björketun

2014

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Sulphur dioxide (SO 2 ), a known industrial pollutant and pulmonary irritant, is emitted to the atmosphere in excess of 120 Mt per annum. Great strides have been taken to reduce SO 2 emissions, but with the growth of specifically China, and to a lesser extent India, it is on the rise again. The electrolysis of aqueous solutions of dissolved SO 2 holds huge environmental potential in that SO 2 is converted to sulphuric acid (H 2 SO 4 ) and at the same time hydrogen gas is produced. A further benefit or incentive is that a sulphur depolarised electrolyser (SDE) operates at an applied potential that is about one volt lower than that of a regular water electrolyser. In taking this technology forward the greatest improvement to be made is in developing a suitable electrocatalyst, which is also the 'lowest hanging fruit' in that very limited research and development has been conducted on the electrocatalyst for this process. In this work, density functional theory is employed to model the electro-oxidation of SO 2 on single crystal planes of the 4d and 5d transition metals. Two reaction mechanisms are considered, a HSO 3 intermediate pathway and a SO 3 intermediate pathway. The binding energies of all intermediates are found to scale with the surface reactivity (measured as the adsorption of OH). Irrespective of the pathway water needs to be activated and reduction of SO 2 to elemental sulphur must be avoided. This requirement alone calls for an electrode potential of at least 0.7-0.8 V for all the investigated transition metals and thus challenges the proclaimed goal to operate the SDE at 0.6 V. A high chemical barrier is further found to severely limit the oxidation reaction on reactive metals. A much higher catalytic activity can be obtained on precious metals but at the cost of running the reaction at high overpotentials.

show abstract

Preparation and characterization of Ir Pt1−O2 anode electrocatalysts for the oxygen evolution reaction

Cited by 30 publications

References 27 publications

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Nanostructured F doped IrO2 electro-catalyst powders for PEM based water electrolysis

H₂ production through electro-oxidation of SO₂: identifying the fundamental limitations

Contact Info

Product

Resources

About

Preparation and characterization of Ir Pt1−O2 anode electrocatalysts for the oxygen evolution reaction

Cited by 30 publications

References 27 publications

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Study of fluorine doped (Nb,Ir)O2 solid solution electro-catalyst powders for proton exchange membrane based oxygen evolution reaction

Nanostructured F doped IrO2 electro-catalyst powders for PEM based water electrolysis

H2 production through electro-oxidation of SO2: identifying the fundamental limitations

Contact Info

Product

Resources

About

H₂ production through electro-oxidation of SO₂: identifying the fundamental limitations