scholarly journals Catalytic Behavior of Iron-Containing Cubic Spinel in the Hydrolysis and Hydrothermolysis of Ammonia Borane

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5422
Author(s):  
Oksana V. Komova ◽  
Valentina I. Simagina ◽  
Alena A. Pochtar ◽  
Olga A. Bulavchenko ◽  
Arcady V. Ishchenko ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ammonia Borane ◽  
Copper Ferrite ◽  
High Catalytic Activity ◽  
Oxide Systems ◽  
Catalytic Behavior ◽  
H2 Generation ◽  
Cobalt Ferrites ◽  
Reduction Of Iron ◽  
Magnetite Fe3o4

The paper presents a comparative study of the activity of magnetite (Fe3O4) and copper and cobalt ferrites with the structure of a cubic spinel synthesized by combustion of glycine-nitrate precursors in the reactions of ammonia borane (NH3BH3) hydrolysis and hydrothermolysis. It was shown that the use of copper ferrite in the studied reactions of NH3BH3 dehydrogenation has the advantages of a high catalytic activity and the absence of an induction period in the H2 generation curve due to the activating action of copper on the reduction of iron. Two methods have been proposed to improve catalytic activity of Fe3O4-based systems: (1) replacement of a portion of Fe2+ cations in the spinel by active cations including Cu2+ and (2) preparation of highly dispersed multiphase oxide systems, involving oxide of copper.

From Ru nanoparticle-encapsulated metal–organic frameworks to highly catalytically active Cu/Ru nanoparticle-embedded porous carbon

2017 ◽  
Vol 5 (10) ◽  
pp. 4835-4841 ◽  
Author(s):  
Pradip Pachfule ◽  
Xinchun Yang ◽  
Qi-Long Zhu ◽  
Nobuko Tsumori ◽  
Takeyuki Uchida ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Temperature ◽  
Porous Carbon ◽  
Metal Organic Frameworks ◽  
Ammonia Borane ◽  
Carbon Composites ◽  
High Catalytic Activity ◽  
Catalytically Active ◽  
Metal Organic

High-temperature pyrolysis of Ru nanoparticle-encapsulated MOF (Ru@HKUST-1) afforded ultrafine Cu/Ru nanoparticle-embedded porous carbon composites (Cu/Ru@C), which show high catalytic activity for ammonia borane hydrolysis.

scholarly journals Ru Nanoparticles Embedded in Cubic Mesoporous Silica SBA-1 as Highly Efficient Catalysts for Hydrogen Generation from Ammonia Borane

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 267 ◽  
Author(s):  
Juti Rani Deka ◽  
Diganta Saikia ◽  
Kuo-Shu Hsia ◽  
Hsien-Ming Kao ◽  
Yung-Chin Yang ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Active Sites ◽  
Hydrogen Generation ◽  
Ammonia Borane ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Porous Support ◽  
H2 Generation ◽  
Ru Nanoparticles ◽  
Cubic Mesoporous

Cubic mesoporous silica SBA-1 functionalized with carboxylic acid (-COOH), namely S1B-C10, is used as a support to fabricate and confine Ru nanoparticles (NPs). The uniformly dispersed organic functional groups in SBA-1 are beneficial in attracting Ru cations, and as a result, homogenously distributed small sized Ru NPs are formed within the mesopores. The prepared Ru@S1B-C10 is utilized as a catalyst for H2 generation from the hydrolysis of ammonia borane (AB). The Ru@S1B-C10 catalyst demonstrates high catalytic activity for H2 generation (202 mol H2 molRu min−1) and lower activation energy (24.13 kJ mol−1) due to the small sized Ru NPs with high dispersion and the support’s interconnected mesoporous structure. The nanosized Ru particles provide abundant active sites for the catalytic reaction to take place, while the interconnected porous support facilitates homogenous transference and easy dispersal of AB molecules to the active sites. The catalyst demonstrates good recycle ability since the accumulation and leaking of NPs throughout catalysis can be effectively prevented by the support.

A stable and efficient 3D cobalt-graphene composite catalyst for the hydrolysis of ammonia borane

2016 ◽  
Vol 6 (19) ◽  
pp. 7186-7192 ◽  
Author(s):  
Mengxiong Li ◽  
Jiantong Hu ◽  
Hongbin Lu
Keyword(s):  
Catalytic Activity ◽  
Cobalt Catalyst ◽  
Ammonia Borane ◽  
Composite Catalyst ◽  
High Catalytic Activity ◽  
Graphene Composite ◽  
3D Composite ◽  
Hydrolysis Of

We synthesized a PEI decorated GO 3D composite supported cobalt catalyst that showed high catalytic activity and stability for the hydrolysis of AB.

Synthesis of Ni-Ru Alloy Nanoparticles and Their High Catalytic Activity in Dehydrogenation of Ammonia Borane

2012 ◽  
Vol 18 (25) ◽  
pp. 7925-7930 ◽  
Author(s):  
Guozhu Chen ◽  
Stefano Desinan ◽  
Renzo Rosei ◽  
Federico Rosei ◽  
Dongling Ma
Keyword(s):  
Catalytic Activity ◽  
Ammonia Borane ◽  
High Catalytic Activity ◽  
Alloy Nanoparticles

scholarly journals Cu0.4Co0.6MoO4 Nanorods Supported on Graphitic Carbon Nitride as a Highly Active Catalyst for the Hydrolytic Dehydrogenation of Ammonia Borane

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 714 ◽  
Author(s):  
Junhao Li ◽  
Fangyuan Li ◽  
Jinyun Liao ◽  
Quanbing Liu ◽  
Hao Li
Keyword(s):  
Catalytic Activity ◽  
Carbon Nitride ◽  
Low Cost ◽  
Ammonia Borane ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
High Catalytic Activity ◽  
High Hydrogen ◽  
Practical Applications ◽  
Highly Active

As a typical chemical hydride, ammonia borane (AB) has received extensive attention because of its safety and high hydrogen storage capacity. The aim of this work was to develop a cost-efficient and highly reactive catalyst for hydrolyzing AB. Herein, we synthesized a series of CuxCo1–xMoO4 dispersed on graphitic carbon nitride (g-C3N4) to dehydrogenate AB. Among those CuxCo1–xMoO4/g-C3N4 catalysts, Cu0.4Co0.6MoO4/g-C3N4 exhibited the highest site time yield (STY) value of 75.7 m o l H 2 m o l c a t − 1   m i n − 1 with a low activation energy of 14.46 kJ mol−1. The STY value for Cu0.4Co0.6MoO4/g-C3N4 was about 4.3 times as high as that for the unsupported Cu0.4Co0.6MoO4, indicating that the g-C3N4 support plays a crucial role in improving the catalytic activity. Considering its low cost and high catalytic activity, our Cu0.4Co0.6MoO4/g-C3N4 catalyst is a strong candidate for AB hydrolysis for hydrogen production in practical applications.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

Ordered Intermetallic Nanoparticles with High Catalytic Activity Prepared by an Electrochemically Induced Phase Transformation

2019 ◽  
Author(s):  
Du Sun ◽  
yunfei wang ◽  
Kenneth Livi ◽  
chuhong wang ◽  
ruichun luo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffusion Mechanism ◽  
Reduction Reaction ◽  
Atomic Scale ◽  
High Catalytic Activity ◽  
Ambient Conditions ◽  
Magnetic Devices ◽  
Disordered Alloys ◽  
Ordered Intermetallic ◽  
Intermetallic Nanoparticles

<div> <p>The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered intermetallic PdBi<sub>2</sub> to ordered intermetallic Pd<sub>3</sub>Bi nanoparticles under ambient conditions by an electrochemically induced phase transition. The low melting point of PdBi<sub>2</sub> corresponds to low vacancy formation energies which enables the facile removal of the Bi from the surface, while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd<sub>3</sub>Bi exhibits 11x and 3.5x higher mass activty and high methanol tolerance for the oxygen reduction reaction compared to Pt/C and Pd/C, respectively,which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble metal rich ordered intermetallic phases with high catalytic activity, and sets forth guidelines for the design of ordered intermetallic compounds under ambient conditions.</p> </div>

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

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