Silver nanocrystal-decorated polyoxometalate single-walled nanotubes as nanoreactors for desulfurization catalysis at room temperature

Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 13334-13340 ◽  
Author(s):  
Hao Zhang ◽  
Xiaobin Xu ◽  
Haifeng Lin ◽  
Muhammad Aizaz Ud Din ◽  
Haiqing Wang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Room Temperature ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Single Walled Nanotubes

Ultrathin nanocrystals generally provide a remarkable catalytic performance due to their high specific surface area and exposure of certain active sites.

scholarly journals Application of CoMn/CoFe layered double hydroxide based on metal-organic frameworks template to activate peroxymonosulfate for 2, 4-dichlorophenol degradation

2021 ◽  
Author(s):  
Chenyu Liu ◽  
Haitong Wei ◽  
Yanhui Gao ◽  
Ning Wang ◽  
Xiaoying Yuan ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
High Specific Surface Area ◽  
State Transformation ◽  
Alkaline Conditions ◽  
Metal Organic

Abstract Metal-Organic Frameworks (MOFs) have unique properties and stable structure, which have been widely used as templates/precursors to prepare well-developed pore structure and high specific surface area materials. In this article, an innovative and facile method of crystal reorganization was designed by using MOFs as sacrificial templates to prepare LDH nano-layer sheet structure through a pseudomorphic conversion process under alkaline conditions. The obtained CoMn-LDH and CoFe-LDH catalysts broke the ligand of MOFs and reorganized the structure on the basis of retaining a high specific surface area and a large number of pores, which have higher specific surface area and well-developed pore structure than LDH catalysts prepared by traditional methods, and thus provide more active sites to activate PMS. Due to the unique framework structure of MOFs, the MOF derived CoMn-LDH and CoFe-LDH catalysts could provide more active sites to activate PMS, and achieve a 2, 4-dichlorophenol (2, 4-DCP) degradation of 99.3% and 99.2% within 20 min, respectively. Besides, the two LDH catalysts displayed excellent degradation performance for bisphenol A (BPA), ciprofloxacin (CIP) and 2, 4-dichlorophenoxyacetic acid (2, 4-D). XPS indicated that the valence state transformation of metal elements participated in PMS activation. EPR manifested sulfate radical () and singlet oxygen (1O2) were the main species for degrading pollutants. In addition, after the three-cycle experiment, the CoMn-LDH and CoFe-LDH catalysts also showed long-term stability with a slight activity decrease in the third cycle. The phytotoxicity assessment determined by the germination of mung beans proved that PMS activation by MOFs-derived LDH catalyst can basically eliminate the phytotoxicity of 2, 4-D solution. This research not only developed high-activity LDH catalysts for PMS activation, but also expanded the environmental applications of MOFs derivants.

scholarly journals High-Level Oxygen Reduction Catalysts Derived from the Compounds of High-Specific-Surface-Area Pine Peel Activated Carbon and Phthalocyanine Cobalt

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3429
Author(s):  
Lei Zhao ◽  
Ziwei Lan ◽  
Wenhao Mo ◽  
Junyu Su ◽  
Huazhu Liang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
High Performance ◽  
Low Cost ◽  
Specific Area ◽  
High Specific Surface Area ◽  
High Catalytic Activity

Non-platinum carbon-based catalysts have attracted much more attention in recent years because of their low cost and outstanding performance, and are regarded as one of the most promising alternatives to precious metal catalysts. Activated carbon (AC), which has a large specific surface area (SSA), can be used as a carrier or carbon source at the same time. In this work, stable pine peel bio-based materials were used to prepare large-surface-area activated carbon and then compound with cobalt phthalocyanine (CoPc) to obtain a high-performance cobalt/nitrogen/carbon (Co-N-C) catalyst. High catalytic activity is related to increasing the number of Co particles on the large-specific-area activated carbon, which are related with the immersing effect of CoPc into the AC and the rational decomposed temperature of the CoPc ring. The synergy with N promoting the exposure of CoNx active sites is also important. The Eonset of the catalyst treated with a composite proportion of AC and CoPc of 1 to 2 at 800 °C (AC@CoPc-800-1-2) is 1.006 V, higher than the Pt/C (20 wt%) catalyst. Apart from this, compared with other AC/CoPc series catalysts and Pt/C (20 wt%) catalyst, the stability of AC/CoPc-800-1-2 is 87.8% in 0.1 M KOH after 20,000 s testing. Considering the performance and price of the catalyst in a practical application, these composite catalysts combining biomass carbon materials with phthalocyanine series could be widely used in the area of catalysts and energy storage.

scholarly journals The Effects of Various Parameters of the Microwave-Assisted Solvothermal Synthesis on the Specific Surface Area and Catalytic Performance of MgF2 Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3566
Author(s):  
Yawen Wang ◽  
Zahra Gohari Bajestani ◽  
Jérôme Lhoste ◽  
Sandy Auguste ◽  
Annie Hémon-Ribaud ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solvothermal Synthesis ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Microwave Assisted ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Nanoparticle Sizes

High-specific-surface-area MgF2 was prepared by microwave-assisted solvothermal synthesis. The influences of the solvent and the magnesium precursors, and the calcination atmospheres, on the nanoparticle sizes and specific surface areas, estimated by X-Ray Powder Diffraction, N2 sorption and TEM analyses, were investigated. Nanocrystallized (~7 nm) magnesium partially hydroxylated fluorides (MgF2−x(OH)x) with significant specific surface areas between 290 and 330 m2∙g−1 were obtained. After activation under gaseous HF, MgF2−x(OH)x catalysts underwent a large decrease of both their surface area and their hydroxide, rates as shown by their 19F and 1H solid-state NMR spectra. Expect for MgF2 prepared from the acetate precursor, an activity of 30–32 mmol/h∙g was obtained which was about 40% higher compared with that of MgF2 prepared using Trifluoroacetate method (21.6 mmol/h∙g).

Bifunctional electrocatalysts of MOF-derived Co–N/C on bamboo-like MnO nanowires for high-performance liquid- and solid-state Zn–air batteries

2018 ◽  
Vol 6 (20) ◽  
pp. 9716-9722 ◽  
Author(s):  
Ya-Nan Chen ◽  
Yibo Guo ◽  
Huijuan Cui ◽  
Zhaojun Xie ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Solid State ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
High Performance ◽  
High Specific Surface Area ◽  
Bifunctional Electrocatalysts ◽  
Nanowire Structure

MnO@Co–N/C composites were fabricated with excellent bifunctional catalytic activity and outstanding performance for both liquid- and solid-state Zn–air batteries. The excellent electrocatalytic activities are attributed to the unique 1D nanowire structure with abundant Co–Nx active sites and a high specific surface area.

scholarly journals The Role of Strontium in CeNiO3 Nano-Crystalline Perovskites for Greenhouse Gas Mitigation to Produce Syngas

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 356
Author(s):  
Naushad Ahmad ◽  
Rizwan Wahab ◽  
Salim Manoharadas ◽  
Basel F. Alrayes ◽  
Munawwer Alam ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Catalytic Performance ◽  
Catalyst Stability ◽  
Methane Reforming ◽  
Metal Support Interaction ◽  
Production Of Hydrogen

The transition metal-based catalysts for the elimination of greenhouse gases via methane reforming using carbon dioxide are directly or indirectly associated with their distinguishing characteristics such as well-dispersed metal nanoparticles, a higher number of reducible species, suitable metal–support interaction, and high specific surface area. This work presents the insight into catalytic performance as well as catalyst stability of CexSr1−xNiO3 (x = 0.6–1) nanocrystalline perovskites for the production of hydrogen via methane reforming using carbon dioxide. Strontium incorporation enhances specific surface area, the number of reducible species, and nickel dispersion. The catalytic performance results show that CeNiO3 demonstrated higher initial CH4 (54.3%) and CO2 (64.8%) conversions, which dropped down to 13.1 and 19.2% (CH4 conversions) and 26.3 and 32.5% (CO2 conversions) for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3, respectively. This drop in catalytic conversions post strontium addition is concomitant with strontium carbonate covering nickel active sites. Moreover, from the durability results, it is obvious that CeNiO3 exhibited deactivation, whereas no deactivation was observed for Ce0.8Sr0.2NiO3 and Ce0.6Sr0.4NiO3. Carbon deposition during the reaction is mainly responsible for catalyst deactivation, and this is further established by characterizing spent catalysts.

scholarly journals Electrospun Nanofibers with High Specific Surface Area to Prepare Modified Electrodes for Electrochemiluminescence Detection of Azithromycin

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Cheng ◽  
Xuenuan Li ◽  
Tianhao Li ◽  
Danfeng Qin ◽  
Tingfan Tang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Active Sites ◽  
Raw Materials ◽  
Modified Electrodes ◽  
Electrospun Nanofibers ◽  
High Sensitivity ◽  
Specific Area ◽  
High Specific Surface Area

Polyacrylonitrile (PAN) and (CH3COO)2Zn were used as raw materials, and carbon nanofibers (CNFs) with high specific surface area were successfully prepared by an electrospinning method. A new method of electrochemiluminescence detection of azithromycin was established by modifying the glassy carbon electrode (GCE). Under the optimal conditions, the electrochemical behavior and electrochemiluminescence behavior of the Ru(bpy)32+-AZM system on the modified electrode were investigated. Owing to the large specific area, more active sites, and promotion of electron transfer, the sensor exhibits high electrocatalytic activity, high sensitivity, a good linear relationship ranging from 8.0 × 10 − 8 to 1.0 × 10 − 4  mol/L, and a low detection limit ( 6.52 × 10 − 8  mol/L). In addition, the good recoveries indicate that the sensor was a promising device for the detection of azithromycin in real samples.

Effects of A-site non-stoichiometry in YxInO3+δ on the catalytic performance during methane combustion

2017 ◽  
Vol 19 (45) ◽  
pp. 30418-30428 ◽  
Author(s):  
Yihong Xiao ◽  
Wanlu Zhu ◽  
Guohui Cai ◽  
Meilian Chen ◽  
Yong Zheng ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Oxygen Vacancies ◽  
Methane Combustion ◽  
Catalytic Performance ◽  
High Specific Surface Area ◽  
Perovskite Catalyst ◽  
Gel Combustion ◽  
A Site

A novel non-stoichiometric YxInO3+δ (YIO-x, 0.8 ≤ x ≤ 1.04) perovskite catalyst with a large number of oxygen vacancies and high specific surface area was synthesized using glycine self-propagating gel combustion.

scholarly journals Nanoporous Quasi-High-Entropy Alloy Microspheres

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Entropy Alloy ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Hierarchical Porous

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.

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