Electrochemical synthesis of ammonia via Mars-van Krevelen mechanism on the (111) facets of group III–VII transition metal mononitrides

Abghoui, Younes; Skúlason, Egill

doi:10.1016/j.cattod.2016.06.009

Cited by 134 publications

(144 citation statements)

References 27 publications

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“…For example, in 2019, Hu et al performed the electrochemical experiment on tetragonal Mo 2 N NPs in combination with 15 N‐lableing tests and found Mo 2 N NPs underwent decomposition instead of NRR‐catalytic activities . Similar observations on VN, NbN and Nb 4 N 5 have been reported by Du et al In order to quantitatively compare the tendency of migration against regeneration, Abghoui et al calculated the activation free energy of both processes . Figure b shows the result in the RS (111) case.…”

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 66%

“…As discussed in Section , TM nitrides have been experimentally fabricated into a wide range of morphologies including NPs, nanowires, nanorods and nanosheets . To investigate the catalytic behavior of TM nitrides in depth, Abghoui et al conducted a series of DFT studies on a wide range of TM nitrides in both rocksalt (RS) and zincblende (ZB) structures . In summary, candidates with high activity (low onset potential) are: VN, CrN, NbN, and ZrN for RS (100) facets; MnN, CrN, VN, MoN, WN, and NbN for RS (111) facets; RuN, CrN, and WN for ZB (110) facets .…”

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

“…When a N‐vacancy is created from the release of the first NH 3 , species like O, OH, and H may compete with N 2 to bind the vacancy site. Abghoui et al has investigated the poisoning problem by calculating the free energy differences between adsorbates (Δ G *2 N −* x , where x = O, OH, or H) . While TM nitrides with RS (100) and ZB facets (with Δ G *2 N −* x < 0) do not suffer from poisoning, MnN and WN with RS(111) facets tend to be poisoned by H and OH as illustrated in Figure 17 a.…”

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

“…b) Calculated activation free energies (Ga) of regenerating the catalyst by N 2 dissociation for replenishment of the N‐vacancy compared with activation free energies of vacancy migration into the bulk. Reproduced with permission . Copyright 2017, Elsevier B.V. c) Most Promising Facets of the Nitride Candidates (Green Background) and Corresponding Potential Window and Current Efficiency for N 2 Electroreduction to NH 3 via a MvK Mechanism on ZrN, NbN, CrN, and VN.…”

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

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Recent Advanced Materials for Electrochemical and Photoelectrochemical Synthesis of Ammonia from Dinitrogen: One Step Closer to a Sustainable Energy Future

Yan

Xia

et al. 2019

Advanced Energy Materials

127

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Ammonia (NH3), an important raw material for chemical industry and agriculture, is also considered to be an intriguing energy storage and transportation media for chemical conversion schemes. The world's primary NH3 supply is based on the natural nitrogen fixation by diazotrophs through an enzymatic nitrogenase process and the industrial nitrogen fixation through a traditional Haber–Bosch process. The natural synthesis of NH3 can hardly meet the rapidly growing global demand. Meanwhile, the industrial NH3 production is still dominated by the high‐temperature and high‐pressure reaction between nitrogen and hydrogen (N2 + 3H2 → 2NH3), requiring intensive energy input and generating massive CO2. Therefore, seeking a breakthrough in the development of catalysts toward efficient ammonia synthesis has become the frontier of energy and chemical conversion schemes. This review summarizes and discusses the recent progress on developing new strategies to optimize the efficiency of NH3 production coupled with renewable energy sources, with a specific focus on electrocatalytic and photoelectrocatalytic conversion of N2 to NH3. The most recent advances in the development of catalytic materials, the design of the reaction systems, and the computational insights for electrochemical and photoelectrochemical ammonia synthesis are covered.

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Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 66%

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

Section: Computational Insight Into Materials Design For Nrrmentioning

confidence: 99%

See 2 more Smart Citations

Recent Advanced Materials for Electrochemical and Photoelectrochemical Synthesis of Ammonia from Dinitrogen: One Step Closer to a Sustainable Energy Future

Yan

Xia

et al. 2019

Advanced Energy Materials

127

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“…To determine the density of surface Ns ites active in the ENRR on the VNO catalyst, we develop anovel quantitative isotopic exchange strategy.T his method is based on the understanding that the ENRR on VNO follows the MvK mechanism, [10,[21][22][23][24] with surface Na ctively involved in the catalytic turnovers.Itfollows that all surface Nsites involved in the ENRR would be replaced by 15 Nw hen the ENRR proceeds with 15 N 2 as the feed, leading to the formation of 14 NH 3 ( Figure 1A). Thus,t he amount of surface Ns ites involved in the ENRR could be determined by quantifying the amount of 14 NH 3 produced.…”

mentioning

confidence: 99%

Quantification of Active Sites and Elucidation of the Reaction Mechanism of the Electrochemical Nitrogen Reduction Reaction on Vanadium Nitride

et al. 2019

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Despite recent intense interest in the development of catalysts for the electrochemical nitrogen reduction reaction (ENRR), mechanistic understanding and catalyst design principles remain lacking. In this work, we develop as trategy to determine the density of initial and steady-state active sites on ENRR catalysts that follow the Mars-van Krevelen mechanism via quantitative isotope-exchange experiments. This method allows the comparison of intrinsic activities of active sites and facilitates the identification and improvement of active-site structures for ENRR. Combined with detailed density functional theory calculations,w es how that the ratelimiting step in the ENRR is likely the initial N Nb ond activation via the addition of ap roton and an electron to the adsorbed N 2 on the Nv acancies to form N 2 H. The methodology developed and mechanistic insights gained in this work could guide the rational catalyst design in the ENRR.Ammonia synthesis via the Haber-Bosch process is ap illar of modern agriculture,which converts the abundant but inert dinitrogen in the atmosphere to the key precursor of nitrogenbased fertilizers (N-fertilizers). [1] Despite more than acentury of optimization, the Haber-Bosch process remains energy and carbon intensive. [2][3][4][5][6][7] Distributed and modular ammonia synthesis via the electrochemical nitrogen reduction reaction (ENRR) at or close to ambient conditions,p owered by renewable electricity is an attractive alternative because it allows as-needed and on-site production of ammonia, and in turn N-fertilizers,from N 2 and water. [3] Widespread adoption of the ENRR for ammonia production could drastically reduce the carbon footprint of agricultural activities.ENRR is also compatible with the intermittencyo fr enewable energy sources,e .g., solar and wind energy,a sa mmonia and Nfertilizers can be produced and stored when renewable electricity is abundant or even in surplus.Ar ecent flurry of studies on the ENRR led to the discovery of many catalysts with remarkable ammonia production rates and selectivities. [8][9][10][11][12][13][14][15][16][17][18] Mechanistic insights gained so far lean heavily on computational investigations, with relatively little experimental input and insufficient theory/experiment integration. Forexample,reported ammonia production rates are typically normalized by the geometric area or electrochemical surface area determined by capacitance measurements, [19] which make the comparison of the intrinsic activity among different catalysts challenging. Catalyst development based on the comparison of (electrochemical) surface area normalized activities risks missing highly active structures/phases if they exist in low densities. Our recent work highlights this risk, as VN 0.7 O 0.45 ,rather than the bulk VN phase,inthe vanadium nitride (referred to as the oxygen-modified VN catalyst, or VNO below) is identified as the active phase. [10] Thus,i dentification and quantification of active sites in the ENRR are key to developing catalyst design principles. [20]...

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Nitrogen Fixation Reaction Derived from Nanostructured Catalytic Materials

Wang

Ichihara

Pang

et al. 2018

Adv Funct Materials

238

197

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An efficient nitrogen fixation reaction is highly desirable for obtaining the essential chemicals and energy carriers but remains a challenge due to the strong nonpolar bonding and considerable activation barrier of the NN triple bond (bond energy 940.95 kJ mol−1). Using an appropriate nanostructured catalyst that strongly interacts with nitrogen could promote adsorption and activation, lowering the energy barrier of nitrogen fixation and thus resulting in a relatively mild reaction. In this article, the review of the recent progress in nanostructured catalytic materials for nitrogen fixation is presented, including a comprehensive introduction and discussion on the pathway and mechanism of nitrogen fixation reaction, the recent achievements of a variety of nanostructured catalysts, and the kinds of catalytic nitrogen fixation reactions they are used in. In addition, the challenges faced by the reaction, strategies of catalyst design, and outlooks for further improving the performance of nitrogen fixation are also highlighted.

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Electrochemical synthesis of ammonia via Mars-van Krevelen mechanism on the (111) facets of group III–VII transition metal mononitrides

Cited by 134 publications

References 27 publications

Recent Advanced Materials for Electrochemical and Photoelectrochemical Synthesis of Ammonia from Dinitrogen: One Step Closer to a Sustainable Energy Future

Recent Advanced Materials for Electrochemical and Photoelectrochemical Synthesis of Ammonia from Dinitrogen: One Step Closer to a Sustainable Energy Future

Quantification of Active Sites and Elucidation of the Reaction Mechanism of the Electrochemical Nitrogen Reduction Reaction on Vanadium Nitride

Nitrogen Fixation Reaction Derived from Nanostructured Catalytic Materials

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