Hollow mesoporous carbon electrode-catalyst for direct methanol fuel cell and preparation thereof
The present invention discloses a novel electrode-catalyst for direct methanol fuel cell prepared by introducing a carbon precursor into pores of a wormhole-like molecular sieve template, carbonizing the carbon precursor, removing the molecular sieve template to obtain a wormhole-like mesoporous carbon having a high specific surface of 800-1000 m 2 /g and a pore size of 4-5 nm, and depositing catalyst metal such as Pt—Ru on the mesoporous carbon.
1. A method for preparing a hollow mesoporous carbon electrode-catalyst, which comprises the following steps:
a) preparing a micro emulsion, which comprises mixing water, a water-insoluble oil, and a surfactant, wherein the volume of said oil is less than the volume of said water;
b) preparing a molecular sieve template for synthesizing a hollow mesoporous carbon material, which comprises preparing an acidic aqueous solution containing a silicon oxide and an alkali metal source dissolved therein, mixing said micro emulsion with said acidic aqueous solution, heating the resulting mixture at 50° C. to 200° C. for a sufficient period of time to form a molecular sieve, and calcining said molecular sieve to obtain a surfactant-free molecular sieve template;
c) introducing a carbon precursor into said molecular sieve template, which comprises impregnating said molecular sieve template with a carbon precursor solution;
d) heating said molecular sieve template impregnated with said carbon precursor in an inert atmosphere to carbonize said carbon precursor contained therein;
e) removing said molecular sieve template to obtain a hollow mesoporous carbon material; and
f) depositing a catalyst metal on said hollow mesoporous carbon material.
2. The method as claimed in claim 1 , wherein the surfactant in Step a) is a non-ionic surfactant.
3. The method as claimed in claim 1 , wherein the silicon oxide and alkali metal source in Step b) is sodium silicate.
4. The method as claimed in claim 1 , wherein said carbon precursor solution in Step c) comprises a solvent and a resin dissolved in said solvent.
5. The method as claimed in claim 4 , wherein said resin comprises a phenolic resin.
6. The method as claimed in claim 1 , wherein said step of removing said molecular sieve template in Step e) comprises using an acid solution to wash said carbonized carbon precursor and molecular sieve template.
7. The method as claimed in claim 1 , wherein said step of depositing a catalyst metal on said hollow mesoporous carbon material in Step f) comprises impregnating said hollow mesoporous carbon material in a solution containing ions of said catalyst metal; and subjecting the impregnated hollow mesoporous carbon material to a reduce treatment, so that said catalyst metal ions are deposited on said hollow mesoporous carbon material in the elemental form.
8. The method as claimed in claim 1 , wherein the catalyst metal in Step f) is selected from a group consisting of Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Sn, Al, and a mixture thereof.
9. The method as claimed in claim 8 , wherein said catalyst metal comprises Pt, Ru, or a mixture thereof.