Controllable synthesis of porous carbon spheres, and electrochemical applications thereof

A porous carbon and spherical technology, applied in the field of preparation of the porous carbon, can solve the problems of ignoring the macroscopic shape

Inactive Publication Date: 2011-06-08
NAT RES COUNCIL OF CANADA
View PDF3 Cites 22 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disclosed techniques only focus on controlling the microstructure of carbon while ignoring the macroscopic speciation

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Controllable synthesis of porous carbon spheres, and electrochemical applications thereof
  • Controllable synthesis of porous carbon spheres, and electrochemical applications thereof
  • Controllable synthesis of porous carbon spheres, and electrochemical applications thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0060] In this example, porous carbon spheres were synthesized through a 22 nm colloidal silica template according to the method detailed above. In this case, sucrose was used as the carbon source with a silicon oxide to carbon weight ratio of 2:1.

[0061] Figure 2a SEM pictures of carbon-silica composite particles synthesized by 22nm colloidal silica template are shown. Composite particles have a complete spherical shape and a smooth surface.

[0062] Figure 2b SEM pictures of carbon spheres after etching silicon oxide are shown. Figure 2c is a magnified photograph of a single carbon sphere. It is clear that the etching process does not destroy the spherical shape of the primary particles. The silicon oxide inclusions are etched from the carbon matrix, which results in honeycomb carbon spheres with many uniform nanometer-sized pores. TEM photograph of a single carbon sphere ( Figure 2d ) shows that the carbon spheres are hollow. Such as image 3 As shown in , th...

Embodiment 2

[0066] To improve the stability of such open framework carbon structures, graphitic carbon sphere structures were introduced by adding a catalytic graphitization step to the procedure described in Example 1. Add transition metal ions such as Fe, Co, Ni or others in the form of salts (chloride, sulfate, nitrate, acetate, etc.) to the precursor solution, and the metal / carbon source weight ratio is from 1:20 to 1:5. The metal or metal oxide nanoparticles derived from the salt decomposition product are used as a catalyst in step (3) to graphitize the porous carbon spheres. Figure 6XRD patterns of porous carbon spheres before and after graphitization are shown. A distinct graphite peak can be seen in the second sample. In addition to the advantage of having a more stable structure, graphitic carbon spheres also have higher electronic conductivity (10 S / cm) than pre-graphitized carbon spheres (~1 S / cm). Using a homemade 4-probe setup, by AC impedance spectroscopy at 1V and 10-10...

Embodiment 3

[0068] One of the examples of the application / use of porous carbon according to the present invention is the use of mesoporous carbon spheres loaded with Pt and Pt alloy catalysts prepared by the co-formation process for oxygen reduction reactions, especially in proton exchange membrane fuel cells. For other applications, other noble metal alloy catalysts such as Pt-Ru for methanol oxidation in DMFCs can be used.

[0069] The step of adding catalyst particles can be done after the formation of the spherical porous carbon, or simultaneously by co-forming. One method is a co-forming procedure; the other is a conventional impregnation procedure (microwave-assisted polyol method).

[0070] A co-formation procedure based on the procedure described above was used to synthesize porous carbon spheres loaded with Pt and Pt alloys. Pt salts or mixtures of Pt and transition metal (Co, Ni, Fe, Mn, etc.) salts are dissolved in reaction precursors including carbon sources (sucrose, pyrrole...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention disclosed relates to porous carbon of spherical morphology having tuned porosity and to a method of making same, comprising: (a) providing a precursor solution, by combining in an aqueous solution a colloidal silica template material and a water-soluble pyrolyzable carbon source, wherein the particle size of the colloidal silica template and the colloidal silica / carbon source weight ratio are controlled, (b) atomizing the precursor solution into small droplets by ultrasonic spray pyrolysis, (c) directing the droplets into a high temperature furnace operating at a temperature of 700-1200 0C, under an inert gas atmosphere, where the droplets are transformed into solid spherical composite carbon / silica particles, (d) collecting the resulting composite carbon / silica particles exiting from the furnace, and (e) removing the silica from the particles, to provide substantially pure porous carbon of spherical morphology having tuned porosity defined by surface area and pore size. The porous carbon according to the invention is used as catalyst supports in PEM fuel cells, as electrodes in supercapacitors and lithium in batteries, for hydrogen storage and as earners for drug delivering.

Description

technical field [0001] The present invention relates to porous carbons of spherical morphology with tuned porosity defined by surface area and pore size, and to methods of preparing said porous carbons. Background technique [0002] Today, energy crisis and environmental pollution are two major challenges facing mankind. People all over the world are showing increasing interest in sustainable and environmentally friendly energy sources and energy devices to replace current petroleum and ICE (internal combustion engine) based energy systems. Electrochemical energy conversion and storage devices including fuel cells, batteries, and capacitors are the most promising avenues to solve global energy and environmental problems. [0003] In these electrochemical systems, carbon materials are the key components to help the successful conversion of chemical energy directly to electrical energy. For example, in proton electrolyte membrane fuel cells, porous carbon is used as a cataly...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/08A61K47/04B01J20/20C01B31/02C01B3/56H01G9/042H01M4/60H01M4/96
CPCC01B3/0021H01G11/24H01G9/058C01B31/00B01J20/20A61K47/02Y02E60/13Y02E60/12A61K9/51H01M4/926H01M4/587Y02E60/325H01M8/04216H01M10/0525B01J20/28057B82Y30/00H01G11/42B01J20/28078B01J20/28019Y02E60/50C01B32/00Y02E60/10Y02E60/32Y10T428/2982Y02P70/50
Inventor 刘汉三张久俊
Owner NAT RES COUNCIL OF CANADA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap