On the origin of high activity of hcp metals for ammonia synthesis

2016 ◽  
Vol 18 (7) ◽  
pp. 5291-5298 ◽  
Author(s):  
Shideh Ahmadi ◽  
Payam Kaghazchi
Keyword(s):  
High Activity ◽  
Ammonia Synthesis

We find that the high activity of nanoparticles of hcp metals (Ru, Os, and Re) for ammonia synthesis is due to the N-induced formation of atomically-rough {134̄2} facets.

Two-Dimensional Transition Metal Borides as High Activity and Selectivity Catalysts for Ammonia Synthesis

Nanoscale ◽  
2021 ◽  
Author(s):  
Haona Zhang ◽  
Shuhua Wang ◽  
Hao Wang ◽  
Baibiao Huang ◽  
Shuping Dong ◽  
...  
Keyword(s):  
Transition Metal ◽  
Specific Surface ◽  
High Activity ◽  
Surface Area ◽  
Active Site ◽  
Ammonia Synthesis ◽  
Two Dimensional ◽  
Large Specific Surface Area ◽  
Site Density ◽  
Metal Borides

In comparison to defect/doping induced activity in materials, transition metal borides with exposed metal atom, large specific surface area and high active site density show advantages as durable and efficient...

Novel preparation of nanocrystalline magnesia-supported caesium-promoted ruthenium catalyst with high activity for ammonia synthesis

2003 ◽  
pp. 2488-2489 ◽  
Author(s):  
Shan Wu ◽  
Jixin Chen ◽  
Xingfang Zheng ◽  
Haisheng Zeng ◽  
Chunming Zheng ◽  
...  
Keyword(s):  
High Activity ◽  
Ammonia Synthesis ◽  
Ruthenium Catalyst

Preparation of High Activity Catalyst for Ammonia Synthesis by Supporting Well-Defined Ru Nanoparticles on γ-Al2O3

2001 ◽  
Vol 30 (12) ◽  
pp. 1332-1333 ◽  
Author(s):  
Akane Miyazaki ◽  
Ioan Balint ◽  
Ken-ichi Aika ◽  
Yoshio Nakano
Keyword(s):  
High Activity ◽  
Ammonia Synthesis ◽  
Ru Nanoparticles ◽  
Activity Catalyst

High Activity Dual Colloid Ammonia Synthesis Catalysts

1987 ◽  
Vol 111 ◽  
Author(s):  
Thomas Henry Vanderspurt ◽  
Michael A. Richard
Keyword(s):  
High Activity ◽  
Ammonia Synthesis ◽  
Iron Alloy ◽  
Synthesis Technique ◽  
New Synthesis ◽  
Synthesis Catalysts ◽  
Iron Alloy Catalysts ◽  
Micro Morphology ◽  
Alloy Catalysts

AbstractA new synthesis technique produces a family of iron and iron alloy catalysts with a micro-morphology uniquely suited for ammonia synthesis catalysts.

scholarly journals Low Apparent Activation Energy of Ammonia Synthesis over Ru Catalyst Supported by Hydrogen Storage Material

2021 ◽  
Author(s):  
kazuma torii ◽  
Takaya Ogawa ◽  
Ryusei Morimoto ◽  
Tetsu Seno ◽  
Hideyuki Okumura ◽  
...  
Keyword(s):  
Activation Energy ◽  
Hydrogen Storage ◽  
Apparent Activation Energy ◽  
High Activity ◽  
Ammonia Synthesis ◽  
Catalytic Performance ◽  
Ruthenium Catalysts ◽  
High Electron ◽  
Hydrogen Storage Material ◽  
Storage Material

<p>Ruthenium is an excellent catalyst for ammonia synthesis and recently shows quite high activity when supported on materials with high electron-donating and hydrogen-absorbing properties. The high activity is generally considered to originate from the two effects: the electron-donating property of the support, which reduces its apparent activation energy (<sup>app</sup>E<sub>a</sub>) to half of pure Ru’s <sup>app</sup>E<sub>a</sub>, and the hydrogen-absorbing property, which increases the active site by suppressing hydrogen poisoning, a drawback of ruthenium catalysts. Here, we investigated the catalytic performance of ruthenium loaded on TiMn<sub>2</sub>, a hydrogen storage material without electron-donating property to ruthenium. Ruthenium on TiMn<sub>2</sub> showed the <sup>app</sup>E<sub>a</sub> reduced by half despite the lack of electron-donating property. It is plausible that the decreased <sup>app</sup>E<sub>a</sub> is due to the elimination of hydrogen over Ru by TiMn<sub>2</sub>. The hydrogen storage capacity is also an essential factor in discussing the <sup>app</sup>E<sub>a</sub>.</p>

Ruthenium Ammonium Chloride as a Precursor for the Preparation of High Activity Catalysts for Ammonia Synthesis

2009 ◽  
Vol 30 (3) ◽  
pp. 185-190 ◽  
Author(s):  
Jun NI ◽  
Rong WANG ◽  
Jianxin LIN ◽  
Kemei WEI
Keyword(s):  
High Activity ◽  
Ammonium Chloride ◽  
Ammonia Synthesis

scholarly journals Low Apparent Activation Energy of Ammonia Synthesis over Ru Catalyst Supported by Hydrogen Storage Material

2021 ◽  
Author(s):  
kazuma torii ◽  
Takaya Ogawa ◽  
Ryusei Morimoto ◽  
Tetsu Seno ◽  
Hideyuki Okumura ◽  
...  
Keyword(s):  
Activation Energy ◽  
Hydrogen Storage ◽  
Apparent Activation Energy ◽  
High Activity ◽  
Ammonia Synthesis ◽  
Catalytic Performance ◽  
Ruthenium Catalysts ◽  
High Electron ◽  
Hydrogen Storage Material ◽  
Storage Material

<p>Ruthenium is an excellent catalyst for ammonia synthesis and recently shows quite high activity when supported on materials with high electron-donating and hydrogen-absorbing properties. The high activity is generally considered to originate from the two effects: the electron-donating property of the support, which reduces its apparent activation energy (<sup>app</sup>E<sub>a</sub>) to half of pure Ru’s <sup>app</sup>E<sub>a</sub>, and the hydrogen-absorbing property, which increases the active site by suppressing hydrogen poisoning, a drawback of ruthenium catalysts. Here, we investigated the catalytic performance of ruthenium loaded on TiMn<sub>2</sub>, a hydrogen storage material without electron-donating property to ruthenium. Ruthenium on TiMn<sub>2</sub> showed the <sup>app</sup>E<sub>a</sub> reduced by half despite the lack of electron-donating property. It is plausible that the decreased <sup>app</sup>E<sub>a</sub> is due to the elimination of hydrogen over Ru by TiMn<sub>2</sub>. The hydrogen storage capacity is also an essential factor in discussing the <sup>app</sup>E<sub>a</sub>.</p>

scholarly journals Highly effective and selective molecular nanowire catalysts for hydrogen and ammonia synthesis

2020 ◽  
Vol 8 (48) ◽  
pp. 26075-26084
Author(s):  
Qian Wu ◽  
Rui Peng ◽  
Baibiao Huang ◽  
Liangzhi Kou ◽  
Ying Dai ◽  
...  
Keyword(s):  
High Activity ◽  
Ammonia Synthesis ◽  
Highly Effective

New types of electrocatalysts with high activity and selectivity are essential for advancing sustainable hydrogen and ammonia productions.

New high-activity catalyst for ammonia synthesis

1982 ◽  
Vol 4 (4) ◽  
pp. 393
Keyword(s):  
High Activity ◽  
Ammonia Synthesis ◽  
Activity Catalyst

High-activity samarium-153-EDTMP therapy followed by autologous peripheral blood stem cell support in unresectable osteosarcoma

2001 ◽  
Vol 40 (06) ◽  
pp. 215-220 ◽  
Author(s):  
S. Bielack ◽  
S. Flege ◽  
J. Eckardt ◽  
J. Sciuk ◽  
H. Jürgens ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
High Activity ◽  
Peripheral Blood ◽  
Peripheral Blood Stem Cell ◽  
Blood Stem Cell ◽  
High Dose ◽  
External Radiotherapy ◽  
Primary Tumor Site ◽  
Hematopoietic Stem

Summary Purpose: Despite highly efficacious chemotherapy, patients with osteosarcomas still have a poor prognosis if adequate surgical control cannot be obtained. These patients may benefit from therapy with radiolabeled phosphonates. Patients and Methods: Six patients (three male, three female; seven to 41 years) with unresectable primary osteosarcoma (n = 3) or unresectable recurrent sites of osteosarcomas (n = 3) were treated with high-activity of Sm-153-EDTMP (150 MBq/kg BW). In all patients autologous peripheral blood stem cells had been collected before Sm-153-EDTMP therapy. Results: No immediate adverse reactions were observed in the patients. In one patient bone pain increased during the first 48 hrs after therapy. Three patients received pain relief. Autologous peripheral blood stem cell reinfusion was performed on day +12 to +27 in all patients to overcome potentially irreversible damage to the hematopoietic stem cells. In three patient external radiotherapy of the primary tumor site was performed after Sm-153-EDTMP therapy and in two of them polychemotherapy was continued. Thirty-six months later one of these patients is still free of progression. Two further patients are still alive. However, they have developed new metastases. The three patients who had no accompanying external radiotherapy, all died of disease progression five to 20 months after therapy. Conclusion: These preliminary results show that high-dose Sm-153-EDTMP therapy is feasible and warrants further evaluation of efficacy. The combination with external radiation and polychemotherapy seems to be most promising. Although osteosarcoma is believed to be relatively radioresistant, the total focal dose achieved may delay local progression or even achieve permanent local tumor control in patients with surgically inaccessible primary or relapsing tumors.

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