Method for producing a porous carbon product

Patent metadata

Field	Value
Publication number	US-9718690-B2
Application number	US-201415022340-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Sep 20, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Methods for producing porous carbon product utilize template material in the form of template particles containing macropores and a polymerizable carbon precursor substance. The macropores of the template are infiltrated with the precursor substance in dissolved or melted form. After carbonization of the infiltrated precursor substance, the template is removed to form the porous carbon product. In order to obtain a carbon structure with hierarchical porosity having a high fraction of mesopores having pore sizes in the range of 2 to 50 nm, after the infiltration and before carbonization, the precursor substance within the macropores of the template is subjected to a treatment at a foaming temperature at which the precursor substance foams under polycondensation and fills the macropores as substantially mesoporous foam, in which at least 70% of the pores have pore sizes in the range of 10 to 150 nm.

First claim

We claim:

1. A method for producing a porous carbon product, comprising the following method steps:
(a) providing a template material in a form of template particles containing macropores,
(b) providing a carbon precursor substance,
(c) infiltrating the macropores of the template with the precursor substance in melted or dissolved form at a temperature Ta,
(d) carbonizing the precursor substance at a temperature Tc, and
(e) removing the template to form the porous carbon product, further comprising after step (c) and prior to step (d) subjecting the precursor substance within the macropores of the template to a treatment at a foam formation temperature Tb, wherein at temperature Tb the precursor substance foams during polycondensation and fills the macropores as a fine-pored foam, and wherein after step (d) the fine-pored foam forms a porous carbon structure in which at least 70% of the pores have pore sizes in a range of 10 nm to 150 nm.

2. The method according to claim 1 , wherein the foam formation temperature Tb has a temperature range of not more than 100° C., and wherein the treatment duration is at least 10 minutes at the foam formation temperature Tb.

3. The method according to claim 1 , wherein during the foam formation treatment the precursor substance separates at least 30% of its initial mass as gas prior to the polycondensation.

4. The method according to claim 1 , wherein a carbohydrate is used as the carbon precursor substance.

5. The method according to claim 1 , wherein the template particles have a non-spherical morphology and are formed as platelets or small rods with a structural ratio of at least 5 and a mean thickness in a range of 5 μm to 100 μm.

6. The method according to claim 1 , wherein the precursor substance is provided in a form of precursor substance particles of a material having a melting temperature below Ta, and wherein the precursor substance particles are mixed with the template particles in a mass ratio in a range between 0.05 and 1.6.

7. The method according to claim 1 , wherein the template material is SiO 2 .

8. The method according to claim 1 , wherein step (a) comprises a soot deposition process comprising converting a feedstock material by hydrolysis or pyrolysis into template material particles and depositing the particles on a deposition surface to form a soot body from the template material, wherein the soot body is comminuted into the template particles.

Assignees

• Heraeus Quarzglas

Inventors

• Neumann Christian
• Otter Matthias
• Becker Jörg
• Pihan Sascha

Classifications

• C04B2111/00853

  in electrochemical cells or batteries, e.g. fuel cells · CPC title

• B01J20/28085 Primary

  being more than 50 nm, i.e. macropores · CPC title

• C04B38/0022

  obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors · CPC title

• C04B35/6303

  Inorganic additives · CPC title

• C04B2111/0081

  as catalysts or catalyst carriers · CPC title