Sonochemical Synthesis and Catalytic Properties of Nanostructured Molybdenum Carbide

1994 ◽  
Vol 351 ◽  
Author(s):  
Kenneth S. Suslick ◽  
Taeghwan Hyeon ◽  
Mingming Fang ◽  
Andrzej A. Cichowlas
Keyword(s):  
Catalytic Activity ◽  
Molybdenum Carbide ◽  
Gas Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
Face Centered Cubic ◽  
Excess Carbon ◽  
Dehydrogenation Of Cyclohexane ◽  
Good Catalytic Activity ◽  
Face Centered

ABSTRACTMolybdenum hexacarbonyl in hexadecane was irradiated with high intensity ultrasound under argon at 90°C to yield face centered cubic molybdenum carbide, Mo2C. After thermal treatment, oxygen and excess carbon were removed to give stoichiometric Mo2C. SEM micrographs showed that the surface was extremely porous. TEM micrographs showed that the solid was an aggregate of particles with diameters of ≈ 2 nm. This material has a very high surface area, 188 m2/g as determined by BET gas adsorption. Catalytic studies have been conducted on the dehydrogenation of cyclohexane and the hydrogenolysis of ethane. The sonochemically prepared Mo2C shows good catalytic activity for the dehydrogenation of cyclohexane with 100% selectivity for formation of benzene without hydrogenolysis to methane. The material revealed poor catalytic activity for the hydrogenolysis of ethane.

scholarly journals Flower-Shaped C-Dots/Co3O4{111} Constructed with Dual-Reaction Centers for Enhancement of Fenton-Like Reaction Activity and Peroxymonosulfate Conversion to Sulfate Radical

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Centers ◽  
Organic Radicals ◽  
The Other ◽  
High Catalytic Activity ◽  
High Adsorption ◽  
High Turnover

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

scholarly journals Glucose/Graphene-Based Aerogels for Gas Adsorption and Electric Double Layer Capacitors

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Kang-Kai Liu ◽  
Biao Jin ◽  
Long-Yue Meng
Keyword(s):  
Gas Adsorption ◽  
High Surface ◽  
Aqueous Media ◽  
High Surface Area ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Mesopore Size Distribution ◽  
Excellent Electrochemical Performance ◽  
Double Layer Capacitors ◽  
Hydrothermal Reduction

In this study, three-dimensional glucose/graphene-based aerogels (G/GAs) were synthesized using the hydrothermal reduction and CO2 activation method. Graphene oxide (GO) was used as a matrix, and glucose was used as a binder for the orientation of the GO morphology in an aqueous media. We determined that G/GAs exhibited narrow mesopore size distribution, a high surface area (763 m2 g−1), and hierarchical macroporous and mesoporous structures. These features contributed to G/GAs being promising adsorbents for the removal of CO2 (76.5 mg g−1 at 298 K), CH4 (16.8 mg g−1 at 298 K), and H2 (12.1 mg g−1 at 77 K). G/GAs presented excellent electrochemical performance, featuring a high specific capacitance of 305.5 F g−1 at 1 A g−1, and good cyclic stability of 98.5% retention after 10,000 consecutive charge-discharge cycles at 10 A g−1. This study provided an efficient approach for preparing graphene aerogels exhibiting hierarchical porosity for gas adsorption and supercapacitors.

scholarly journals Facile synthesis of high surface area molybdenum carbide nanoparticles

2018 ◽  
Vol 102 (6) ◽  
pp. 3738-3744 ◽  
Author(s):  
Shanti Kiran Nayak ◽  
Angelica D. Benavidez ◽  
Fernando H. Garzon
Keyword(s):  
Surface Area ◽  
Molybdenum Carbide ◽  
High Surface ◽  
High Surface Area ◽  
Facile Synthesis

scholarly journals High surface area nitrogen-functionalized Ni nanozymes for efficient peroxidase-like catalytic activity

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0257777
Author(s):  
Anuja Tripathi ◽  
Kenneth D. Harris ◽  
Anastasia L. Elias
Keyword(s):  
Catalytic Activity ◽  
Plasma Treatment ◽  
Surface Composition ◽  
Point Of Care ◽  
High Surface ◽  
Effective Means ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Optimal Time ◽  
Ammonia Plasma

Nitrogen-functionalization is an effective means of improving the catalytic performances of nanozymes. In the present work, plasma-assisted nitrogen modification of nanocolumnar Ni GLAD films was performed using an ammonia plasma, resulting in an improvement in the peroxidase-like catalytic performance of the porous, nanostructured Ni films. The plasma-treated nanozymes were characterized by TEM, SEM, XRD, and XPS, revealing a nitrogen-rich surface composition. Increased surface wettability was observed after ammonia plasma treatment, and the resulting nitrogen-functionalized Ni GLAD films presented dramatically enhanced peroxidase-like catalytic activity. The optimal time for plasma treatment was determined to be 120 s; when used to catalyze the oxidation of the colorimetric substrate TMB in the presence of H2O2, Ni films subjected to 120 s of plasma treatment yielded a much higher maximum reaction velocity (3.7⊆10−8 M/s vs. 2.3⊆10−8 M/s) and lower Michaelis-Menten coefficient (0.17 mM vs. 0.23 mM) than pristine Ni films with the same morphology. Additionally, we demonstrate the application of the nanozyme in a gravity-driven, continuous catalytic reaction device. Such a controllable plasma treatment strategy may open a new door toward surface-functionalized nanozymes with improved catalytic performance and potential applications in flow-driven point-of-care devices.

scholarly journals Metal Nanoparticles as Green Catalysts

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3602 ◽  
Author(s):  
Neel Narayan ◽  
Ashokkumar Meiyazhagan ◽  
Robert Vajtai
Keyword(s):  
Catalytic Activity ◽  
Composite Materials ◽  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Significant Role ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Materials Development

Nanoparticles play a significant role in various fields ranging from electronics to composite materials development. Among them, metal nanoparticles have attracted much attention in recent decades due to their high surface area, selectivity, tunable morphologies, and remarkable catalytic activity. In this review, we discuss various possibilities for the synthesis of different metal nanoparticles; specifically, we address some of the green synthesis approaches. In the second part of the paper, we review the catalytic performance of the most commonly used metal nanoparticles and we explore a few roadblocks to the commercialization of the developed metal nanoparticles as efficient catalysts.

scholarly journals Effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts supported on carbon nanotubes in Fischer–Tropsch synthesis

2019 ◽  
Vol 44 (4) ◽  
pp. 316-323 ◽  
Author(s):  
Ali Nakhaei Pour ◽  
Mohammadreza Housaindokht
Keyword(s):  
Catalytic Activity ◽  
Cobalt Catalysts ◽  
Crystal Phase ◽  
Microemulsion System ◽  
Face Centered Cubic ◽  
Metallic Cobalt ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Hexagonal Close Packed ◽  
Face Centered

The effects of metallic cobalt crystal phase on catalytic activity of cobalt catalysts in the Fischer–Tropsch synthesis were investigated in a continuous spinning basket reactor. The cobalt catalysts were prepared by impregnation of the cobalt active phase in a microemulsion system on multiwall carbon nanotube supports. A series of cobalt catalysts with different Co particle sizes was prepared by variation of the water-to-surfactant molar ratio from 2 to 12 in the microemulsion system. The X-ray diffraction results validate a complex composition of cobalt phases containing cobalt oxides and metallic cobalt with hexagonal close-packed and face-centered cubic phases. The results show that larger cobalt particles exhibit more face-centered cubic and less hexagonal close-packed metallic cobalt. The experimental results show that the catalysts with higher fractions of hexagonal close-packed phase exhibited higher conversion in the Fischer–Tropsch reaction.

Large-scale and facile synthesis of a porous high-entropy alloy CrMnFeCoNi as an efficient catalyst

2020 ◽  
Vol 8 (35) ◽  
pp. 18318-18326 ◽  
Author(s):  
Hailong Peng ◽  
Yangcenzi Xie ◽  
Zicheng Xie ◽  
Yunfeng Wu ◽  
Wenkun Zhu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
High Entropy Alloy ◽  
Facile Synthesis ◽  
Efficient Catalyst ◽  
High Entropy

Porous high entropy alloy CrMnFeCoNi exhibited remarkable catalytic activity and stability toward p-nitrophenol hydrogenation. The enhanced catalytic performance not only resulted from the high surface area, but also from exposed high-index facets with terraces.

Sign in / Sign up

Export Citation Format

Share Document