Catalytic and electrocatalytic synthesis of NH3 in a H+ conducting cell by using an industrial Fe catalyst

Ouzounidou, Martha; Skodra, Aglaia; Kokkofitis, Christos; Stoukides, Michael

doi:10.1016/j.ssi.2006.11.019

Cited by 84 publications

(59 citation statements)

References 23 publications

(44 reference statements)

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“…The analysis presented above and shown in Fig. 7 can explain why the kinetics of N 2 reduction in the experimental studies carried out so far [21,22,23,24,25,26,27,28] have been too slow in comparison to H 2 production. The Ru and Pt electrodes which were usually used would have been covered with hydrogen at negative bias and nitrogen would not have been able to adsorb and get reduced to ammonia.…”

Section: Volcano Plots For Ammonia Formationmentioning

confidence: 88%

“…The energy input needed for articial processes is estimated to be as large as for the biological N 2 xation [20]. For the electro-catalytic N 2 reduction, various types of electrolytes and electrode materials have been tried, but the kinetics are too slow for practical applications [21,22,23,24,25,26,27,28]. Little is known about the mechanism of this process and in most cases hydrogen gas is formed more readily than hydrogenation of N 2 .…”

Section: Introductionmentioning

confidence: 99%

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A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction

Skúlason

Bligaard

Guðmundsdóttir

et al. 2012

Phys. Chem. Chem. Phys.

1,299

1,468

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Theoretical studies of the possibility of forming ammonia electrochemically at ambient temperature and pressure are presented. Density functional theory calculations were used in combination with the computational standard hydrogen electrode to calculate the free energy prole for the reduction of N 2 admolecules and N adatoms on several close-packed and stepped transition metal surfaces in contact with an acidic electrolyte. Trends in the catalytic activity were calculated for a range of transition metal surfaces and applied potentials under the assumption that the activation energy barrier scales with the free energy dierence in each elementary step. The most active surfaces, on top of the volcano diagrams, are Mo, Fe, Rh, and Ru, but hydrogen gas formation will be a competing reaction reducing the faradaic eciency for ammonia production. Since the early transition metal surfaces, such as Sc, Y, Ti, and Zr bind N-adatoms more strongly than H-adatoms, a signicant production of ammonia compared with hydrogen gas can be expected on those metal electrodes when a bias of -1 V to -1.5 V vs. SHE is applied. Defect-free surfaces of the early transition metals are catalytically more active than their stepped counterparts.

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Section: Volcano Plots For Ammonia Formationmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction

Skúlason

Bligaard

Guðmundsdóttir

et al. 2012

Phys. Chem. Chem. Phys.

1,299

1,468

View full text Add to dashboard Cite

show abstract

“…These results were subsequently re-visited by Stoukides et al, who suggested that the cause of the NEMCA effect in this instance was a lowering of the Fe catalyst work function by the electrochemically-driven influx of protons from the anode, with this lowering of the work function facilitating N 2 chemisorption (generally held to be the rate-determining step) on the Fe catalyst. 17 Molten salt electrolytes have also been explored for the electrosynthesis of NH 3 from its elements.…”

Section: Electrochemical Ammonia Production From N 2 and Hmentioning

confidence: 99%

Recent progress towards the electrosynthesis of ammonia from sustainable resources

2017

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Ammonia (NH 3 ) is a key commodity chemical of vital importance for fertilizers. It is made on an industrial scale via the Haber Bosch process, which requires significant infrastructure to be in place such that ammonia is generally made in large, centralized facilities. If ammonia could be produced under less demanding conditions, then there would be the potential for smaller devices to be used to generate ammonia in a decentralized manner for local consumption. Electrochemistry has been proposed as an enabling technology for this purpose as it is relatively simple to scale electrolytic devices to meet almost any level of demand. Moreover, it is possible to envisage electrosynthetic cells where water could be oxidized to produce protons and electrons at the anode which could then be used to reduce and protonate nitrogen to give ammonia at the cathode. If this nitrogen were sourced from the air, then the only required infrastructure for this process would be supplies of water, air and electricity, the latter of which could be provided by renewables. Hence an electrosynthetic cell for ammonia production could allow NH 3 to be generated sustainably in small, low-cost devices requiring only minimal facilities. In this review, we describe recent progress towards such electrosynthetic ammonia production devices, summarizing also some of the seminal literature in the field. Comparison is made between the various different approaches that have been taken, and the key remaining challenges in the electrosynthesis of ammonia are highlighted.

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“…Since then, based on the pioneering work of Marnellos and Stoukides, considerable efforts have focused on various aspects of the cell reactor in order to improve the ammonia formation rate [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Stoukides and coworkers research group has studied in detail the ammonia synthesis reaction in solid state proton conducting cells on Pd electrodes and on an industrial Fe catalyst by using strontia-ceria-ytterbia electrolytes [8][9][10]. More recently, they first demonstrated the feasibility of an electrocatalytic process in which ammonia was synthesized from steam and nitrogen by using either oxygen ion or proton conducting solid electrolyte cells [11].…”

Section: Introductionmentioning

confidence: 99%

Ammonia synthesis at atmospheric pressure using a reactor with thin solid electrolyte BaCe0.85Y0.15O3−α membrane

Wang

Cao

Gao³

et al. 2010

Journal of Membrane Science

101

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Catalytic and electrocatalytic synthesis of NH3 in a H+ conducting cell by using an industrial Fe catalyst

Cited by 84 publications

References 23 publications

A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction

A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction

Recent progress towards the electrosynthesis of ammonia from sustainable resources

Ammonia synthesis at atmospheric pressure using a reactor with thin solid electrolyte BaCe0.85Y0.15O3−α membrane

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Catalytic and electrocatalytic synthesis of NH3 in a H+ conducting cell by using an industrial Fe catalyst

Cited by 84 publications

References 23 publications

A theoretical evaluation of possible transition metal electro-catalysts for N2reduction

A theoretical evaluation of possible transition metal electro-catalysts for N2reduction

Recent progress towards the electrosynthesis of ammonia from sustainable resources

Ammonia synthesis at atmospheric pressure using a reactor with thin solid electrolyte BaCe0.85Y0.15O3−α membrane

Contact Info

Product

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A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction

A theoretical evaluation of possible transition metal electro-catalysts for N₂reduction