High surface area activated carbon foam
An activated carbon foam material with improved graphitizability is formed by including an oxidation promoting metal-containing additive into the carbon foam and subsequently heat treating the foam in a reactive atmosphere. The oxidation promoting metal-containing additive greatly improves the development of the carbon foam's ramified pore system resulting in a carbon foam with a much greater surface area. This inventive foam may be created by introducing the oxidation promoting metal by way of an oxidation catalyst during the polymerization of the phenolic resin or as a inorganic chemical activating agent to the formed phenolic resin. The foam is then heated in a reactive atmosphere to produce an activated foam with a surface area of from about 200 m 2 /g to about 3000 m 2 /g.
1 . A method for creating an activated carbon foam, which comprises the steps of:
a) polymerizing a phenol-aldehyde mixture with a metal-containing oxidation catalyst to form a metal-containing resin article;
b) foaming the metal-containing resin article to create a metal-impregnated phenolic foam;
c) carbonizing the metal-impregnated phenolic foam to create an oxidizable carbon foam;
d) heating the oxidizable carbon foam in a reactive atmosphere to create an activated carbon foam.
2 . The method of claim 1 wherein the metal-containing oxidation catalyst is sodium hydroxide.
3 . The method of claim 1 wherein the metal-containing oxidation catalyst includes an oxidation promoting metal containing additive selected from the group consisting of sodium, potassium, alkaline earth metals, zinc and combinations thereof.
4 . The method of claim 1 wherein step d) comprises heating the oxidizable carbon foam to a temperature of from about 500° C. to about 1000° C.
5 . The method of claim 1 wherein the reactive atmosphere of step d) is air.
6 . The method of claim 1 wherein the reactive atmosphere of step d) is carbon dioxide.
7 . The method of claim 1 wherein the reactive atmosphere of step d) is ozone.
8 . The method of claim 1 wherein the reactive atmosphere of step d) is oxygen.
9 . The method of claim 1 wherein the reactive atmosphere of step d) is steam.
10 . The method of claim 1 wherein the activated carbon foam has a surface area of from about 200 m 2 /g to about 3000 m 2 /g.
11 . A method for creating activated carbon foam, which comprises the steps of:
a) mixing an inorganic chemical activating agent with a resin precursor to create a mixed resin precursor;
b) producing a phenolic foam from the mixed resin precursor;
c) carbonizing the phenolic foam to create an oxidizable carbon foam;
d) heating the oxidizable carbon foam in a reactive atmosphere to create an activated carbon foam.
12 . The method of claim 11 wherein the inorganic chemical activating agent is a metal oxide.
13 . The method of claim 11 wherein the inorganic chemical activating agent is a metal chloride.
14 . An activated carbon foam comprising a carbon foam with a surface area of from about 200 m 2 /g to about 3000 m 2 /g.
15 . The foam of claim 14 wherein the surface area of the carbon foam is from about 700 m 2 /g to about 2000 m 2 /g.
16 . The foam of claim 14 further comprising an oxidation promoting metal-containing additive dispersed through the carbon foam's structure.
17 . The foam of claim 16 wherein the oxidation promoting metal-containing additive is a metal oxide.
18 . The foam of claim 16 wherein the oxidation promoting metal-containing additive is a metal chloride.
19 . The foam of claim 16 wherein the metal of the oxidation promoting metal-containing additive is selected from the group consisting of sodium, potassium, zinc, alkaline earth metals, and combinations thereof.
20 . The foam of claim 16 wherein the activated carbon foam has an oxidation promoting metal-containing additive content of from about 0.1 to about 1.5 by weight.
21 . An activated carbon foam exhibiting a weight-loss of about 25% to about 50% when compared to the same carbon foam in an unactivated condition.