Cobalt molybdenum bimetallic nitride catalysts for ammonia synthesis

Kojima, Ryoichi; Aika, Ken‐ichi

doi:10.1016/s0926-860x(01)00678-0

Cited by 79 publications

(51 citation statements)

References 19 publications

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“…Much of the focus has been on bulk and supported VN, Mo 2 N, W 2 N and Mo/W-based bimetallic (oxy) nitrides due to their competitiveness in NH 3 synthesis [1][2][3], CO hydrogenation [4], NO removal [5][6][7][8][9][10][11][12], hydrazine decomposition [13][14][15], hydrogenation (HYN), hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodeoxygenation (HDO) [16][17][18] reactions. Being poor in thermal stability, the nitrides of Fe, Co, Re (Group VII-VIII) received far less attention in comparison to their Group V-VI (e.g., V, Mo, W) counterparts [19].…”

Section: Introductionmentioning

confidence: 99%

Redox Properties of Cobalt Nitrides for NO Dissociation and Reduction

Yao

Zhu

et al. 2009

Catal Lett

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Section: Introductionmentioning

confidence: 99%

Redox Properties of Cobalt Nitrides for NO Dissociation and Reduction

Yao

Zhu

et al. 2009

Catal Lett

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“…To date, they have found application as catalysts for a wide-range of reactions including ammonia synthesis and decomposition [4][5][6][7][8][9][10][11][12], hydrazine decomposition [13], hydrotreating [2,4] and the reduction of nitric oxide [14][15][16]. Recent studies have also sought to determine the reactivity of lattice nitrogen species in interstitial nitrides to investigate the possibility of nitrogen transfer catalysis, in a manner analogous to the Mars-van Krevelen mechanism in metal oxides [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Nitridation of MoO3/HZSM-5 and Fe-MoO3/HZSM-5

et al. 2009

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Thermal treatment and subsequent ammonolysis of MoO 3 /H-ZSM-5 is shown to be an effective means for the preparation of zeolite dispersed nitrided molybdenum species. However, it is unlikely that these species reflect the bulk structures formed by analogous treatment of bulk MoO 3 precursor. The inclusion of low levels of Fe as a dopant does not produce any apparent effects on the Mo XPS spectra, although the amount of N incorporation is increased, and iron is shown to be reduced to Fe 0 . FTIR studies evidence the migration of molybdenum oxo species into the zeolite at the temperatures employed.

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“…The catalytic NH 3 synthesis is very attractive as a model reaction in the fundamental studies, too [2]. For the above reasons, the researchers from industrial centres and academia are still active in the field of NH 3 synthesis and they try to work out a completely new catalyst [1,[3][4][5][6][7][8][9][10] or to improve the formula and properties of the conventional iron one [11][12][13][14][15]. Among several new catalytic systems investigated in the last 30 years, only ruthenium supported on high surface area graphite (HSAG) was implemented to the industrial practice so far.…”

Section: Introductionmentioning

confidence: 99%

Ammonia synthesis over the Ba-promoted ruthenium catalysts supported on boron nitride

et al. 2005

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Barium promoted ruthenium catalysts deposited on the boron nitride supports were characterised (XRD, O 2 and CO chemisorption) and tested in NH 3 synthesis. Prior to use, the raw BN materials marked as BNS (Starck, 96 m 2 /g) and HCV (Advanced Ceramics Corporation Cleveland USA, 40 m 2 /g) were heated in an ammonia stream at 700-800°C for 120 h. As a result, the oxygen content was reduced from 7.0 at% (BNS) to 3.5 at% (BNS NH3 ) and from 3.8 to 2.7 at% (HCV NH3 ), as evidenced by XPS. The kinetic studies of NH 3 synthesis (63 or 90 bar; H 2 :N 2 = 3:1) revealed that the catalysts based on the modified supports were more active, respectively, than those derived from starting nitrides, the difference being especially pronounced in the case of BNS and BNS NH3 . Studies of the catalysts activation have shown, in turn, that the stabilisation in a H 2 :N 2 = 3:1 mixture at 1 bar is very slow, i.e. the reaction rate increases slowly versus time on stream even at a high temperature of 550 -600°C. Stabilisation is faster and the NH 3 synthesis rates are higher when the activation is performed with an ammonia rich mixture (10% NH 3 in H 2 :N 2 = 3:1) flowing under high pressure of 90 bar. It is suggested that boron oxide (an impurity) acts as a deactivating agent for Ba-Ru/BN and that the reaction between NH 3 and B 2 O 3 (B 2 O 3 + 2NH 3 = 2BN + 3H 2 O) is responsible for the activity increase. A poisoning mechanism of B 2 O 3 is discussed.

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Cobalt molybdenum bimetallic nitride catalysts for ammonia synthesis

Cited by 79 publications

References 19 publications

Redox Properties of Cobalt Nitrides for NO Dissociation and Reduction

Redox Properties of Cobalt Nitrides for NO Dissociation and Reduction

Nitridation of MoO3/HZSM-5 and Fe-MoO3/HZSM-5

Ammonia synthesis over the Ba-promoted ruthenium catalysts supported on boron nitride

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