Confining Pt nanoparticles in porous carbon structures for achieving durable electrochemical performance

Nanoscale ◽  
2014 ◽  
Vol 6 (20) ◽  
pp. 11863-11870 ◽  
Author(s):  
C. Yang ◽  
M. Zhou ◽  
Q. Xu
Keyword(s):  
Electrochemical Performance ◽  
Porous Carbon ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Carbon Structure ◽  
Carbon Structures ◽  
Improved Stability

Uniformly confining Pt nanoparticles in porous carbon structure can give rise to remarkably improved stability and long-term catalytic performance for carbon-supported Pt electrocatalsyts.

Three-dimensional freestanding hierarchically porous carbon materials as binder-free electrodes for supercapacitors: high capacitive property and long-term cycling stability

2016 ◽  
Vol 4 (15) ◽  
pp. 5623-5631 ◽  
Author(s):  
Fujun Miao ◽  
Changlu Shao ◽  
Xinghua Li ◽  
Kexin Wang ◽  
Na Lu ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Three Dimensional ◽  
Hierarchically Porous ◽  
Symmetric Supercapacitor ◽  
Binder Free ◽  
Capacitive Property ◽  
Electrodes For Supercapacitors

Three-dimensional freestanding hierarchically porous carbon was successfully fabricated and assembled in a symmetric supercapacitor presenting outstanding electrochemical performance.

scholarly journals Laser Pyrolysis of Imprinted Furan Pattern for the Precise Fabrication of Microsupercapacitor Electrodes

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 746 ◽  
Author(s):  
Jina Jang ◽  
Jeong Woo Yeom ◽  
Won Kyu Kang ◽  
Muhammad Refatul Haq ◽  
Xun Lu ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Carbon Films ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Ambient Conditions ◽  
Carbon Structure ◽  
Electrically Conductive ◽  
Laser Pyrolysis ◽  
Carbon Structures ◽  
Conventional Laser

The design or dimension of micro-supercapacitor electrodes is an important factor that determines their performance. In this study, a microsupercapacitor was precisely fabricated on a silicon substrate by irradiating an imprinted furan micropattern with a CO2 laser beam under ambient conditions. Since furan is a carbon-abundant polymer, electrically conductive and porous carbon structures were produced by laser-induced pyrolysis. While the pyrolysis of a furan film in a general electric furnace resulted in severe cracks and delamination, the laser pyrolysis method proposed herein yielded porous carbon films without cracks or delamination. Moreover, as the imprinting process already designated the furan area for laser pyrolysis, high-precision patterning was achieved in the subsequent laser pyrolysis step. This two-step process exploited the superior resolution of imprinting for the fabrication of a laser-pyrolyzed carbon micropattern. As a result, the technical limitations of conventional laser direct writing could be overcome. The laser-pyrolyzed carbon structure was employed for microsupercapacitor electrodes. The microsupercapacitor showed a specific capacitance of 0.92 mF/cm2 at 1 mA/cm2 with a PVA-H2SO4 gel electrolyte, and retained an up to 88% capacitance after 10,000 charging/discharging cycles.

Co2P nanoparticle/multi-doped porous carbon nanosheets for the oxygen evolution reaction

2021 ◽  
Author(s):  
Xinxin Sang ◽  
Hengbo Wu ◽  
Nan Zang ◽  
Huilian Che ◽  
Dongyin Liu ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Porous Carbon ◽  
Oxygen Evolution Reaction ◽  
Catalytic Performance ◽  
Carbon Nanosheets

Co2P hybridized with multi-doped carbon nanoleaves is obtained via direct carbonization of ZIF-L/PEI/PA and show good electro-catalytic performance in OER.

scholarly journals Electron donation of non-oxide supports boosts O2 activation on nano-platinum catalysts

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Gan ◽  
Jingxiu Yang ◽  
David Morris ◽  
Xuefeng Chu ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Nitrogen Vacancy ◽  
Innovative Strategy ◽  
Oxide Supports ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Electron Sink ◽  
Nitrogen Vacancies

AbstractActivation of O2 is a critical step in heterogeneous catalytic oxidation. Here, the concept of increased electron donors induced by nitrogen vacancy is adopted to propose an efficient strategy to develop highly active and stable catalysts for molecular O2 activation. Carbon nitride with nitrogen vacancies is prepared to serve as a support as well as electron sink to construct a synergistic catalyst with Pt nanoparticles. Extensive characterizations combined with the first-principles calculations reveal that nitrogen vacancies with excess electrons could effectively stabilize metallic Pt nanoparticles by strong p-d coupling. The Pt atoms and the dangling carbon atoms surround the vacancy can synergistically donate electrons to the antibonding orbital of the adsorbed O2. This synergistic catalyst shows great enhancement of catalytic performance and durability in toluene oxidation. The introduction of electron-rich non-oxide substrate is an innovative strategy to develop active Pt-based oxidation catalysts, which could be conceivably extended to a variety of metal-based catalysts for catalytic oxidation.

scholarly journals Digitally Patterned Mesoporous Carbon Nanostructures of Colorless Polyimide for Transparent and Flexible Micro-Supercapacitor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2547
Author(s):  
Hyeonwoo Kim ◽  
Suwon Hwang ◽  
Taeseung Hwang ◽  
Jung Bin In ◽  
Junyeob Yeo
Keyword(s):  
Carbon Nanostructures ◽  
Specific Area ◽  
Bending Test ◽  
Chemical Compositions ◽  
Carbon Structure ◽  
Carbon Structures ◽  
Direct Laser ◽  
Mechanical Bending ◽  
Minimal Reduction ◽  
High Flexibility

Here, we demonstrate the fabrication of a flexible and transparent micro-supercapacitor (MSC), using colorless polyimide (CPI) via a direct laser writing carbonization (DLWC) process. The focused laser beam directly carbonizes the CPI substrate and generates a porous carbon structure on the surface of the CPI substrate. Fluorine, which is one of the chemical compositions of CPI, can enhance the specific area and the conductivity of the carbon electrode by creating micropores in carbon structures during carbonization. Thus, the fabricated carbonized CPI-based MSC shows enhanced specific capacitance (1.20 mF at 10 mV s−1) and better transmittance (44.9%) compared to the conventional PI-based MSC. Additionally, the fabricated carbonized CPI-based MSC shows excellent cyclic performance with minimal reduction (<~10%) in 3000 cycles and high capacitance retention under mechanical bending test conditions. Due to its high flexibility, transparency, and capacitance, we expect that carbonized CPI-based MSC can be further applied to various flexible and transparent applications.

scholarly journals Tuning the Reaction Selectivity over MgAl Spinel-Supported Pt Catalyst in Furfuryl Alcohol Conversion to Pentanediols

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 415
Author(s):  
Xinsheng Li ◽  
Jifeng Pang ◽  
Jingcai Zhang ◽  
Xianquan Li ◽  
Yu Jiang ◽  
...  
Keyword(s):  
Furfuryl Alcohol ◽  
Pt Nanoparticles ◽  
Catalytic Performance ◽  
Major Product ◽  
Pt Catalyst ◽  
Reaction Products ◽  
Strong Base ◽  
Reaction Selectivity ◽  
Supported Pt Catalysts ◽  
Alcohol Conversion

Catalytic conversion of biomass-derived feedstock to high-value chemicals is of remarkable significance for alleviating dependence on fossil energy resources. MgAl spinel-supported Pt catalysts were prepared and used in furfuryl alcohol conversion. The approaches to tune the reaction selectivity toward pentanediols (PeDs) were investigated and the catalytic performance was correlated to the catalysts’ physicochemical properties based on comprehensive characterizations. It was found that 1–8 wt% Pt was highly dispersed on the MgAl2O4 support as nanoparticles with small sizes of 1–3 nm. The reaction selectivity did not show dependence on the size of Pt nanoparticles. Introducing LiOH onto the support effectively steered the reaction products toward the PeDs at the expense of tetrahydrofurfuryl alcohol (THFA) selectivity. Meanwhile, the major product in PeDs was shifted from 1,5-PeD to 1,2-PeD. The reasons for the PeDs selectivity enhancement were attributed to the generation of a large number of medium-strong base sites on the Li-modified Pt catalyst. The reaction temperature is another effective factor to tune the reaction selectivity. At 230 °C, PeDs selectivity was enhanced to 77.4% with a 1,2-PeD to 1,5-PeD ratio of 3.7 over 4Pt/10Li/MgAl2O4. The Pt/Li/MgAl2O4 catalyst was robust to be reused five times without deactivation.

scholarly journals Ruling Factors in Cinnamaldehyde Hydrogenation: Activity and Selectivity of Pt-Mo Catalysts

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 362
Author(s):  
Marta Stucchi ◽  
Maela Manzoli ◽  
Filippo Bossola ◽  
Alberto Villa ◽  
Laura Prati
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pt Nanoparticles ◽  
Carbon Support ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Hydrogenation Catalysts ◽  
Cinnamaldehyde Hydrogenation ◽  
Transmission Electron ◽  
Heat Treated ◽  
Heating Treatment

To obtain selective hydrogenation catalysts with low noble metal content, two carbon-supported Mo-Pt bimetallic catalysts have been synthesized from two different molybdenum precursors, i.e., Na2MoO4 and (NH4)6Mo7O24. The results obtained by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) combined with the presence and strength of acid sites clarified the different catalytic behavior toward cinnamaldehyde hydrogenation. After impregnating the carbon support with Mo precursors, each sample was used either as is or treated at 400 °C in N2 flow, as support for Pt nanoparticles (NPs). The heating treatment before Pt deposition had a positive effect on the catalytic performance. Indeed, TEM analyses showed very homogeneously dispersed Pt NPs only when they were deposited on the heat-treated Mo/C supports, and XPS analyses revealed an increase in both the exposure and reduction of Pt, which was probably tuned by different MoO3/MoO2 ratios. Moreover, the different acid properties of the catalysts resulted in different selectivity.

ZnCl2 regulate flax-based porous carbon fiber for long cycle stability supercapacitors

2021 ◽  
Author(s):  
Gaigai Duan ◽  
Luying Zhao ◽  
Lian Chen ◽  
Feng Wang ◽  
Shuijian He ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Electrochemical Performance ◽  
Porous Carbon ◽  
Low Cost ◽  
Flax Fiber ◽  
Cycle Stability ◽  
Long Cycle

The flax fiber with abundant sources and low cost is an excellent precursor of carbon fiber for supercapacitor. At present, it is very attractive designing high electrochemical performance electrode via...

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