Low temperature synthesis of aluminum hydr(oxide) inside porous media
Preparing a porous hybrid media includes contacting porous media (e.g., strong base ion-exchange media) with an aqueous solution including aluminum ions to yield a aluminum-ion-containing porous media, contacting the aluminum-ion containing porous media with a reducing agent to impregnate elemental aluminum in the porous media, and oxidizing the elemental aluminum to yield a porous hybrid media including aluminum hydr(oxide) impregnated in the porous media. In some cases, a pH of an aqueous mixture including the aluminum-ion-containing porous media may be adjusted to form a floc including aluminum hydroxide, and the aluminum hydroxide-containing porous media may be contacted with a reducing agent to yield a porous hybrid media including aluminum hydr(oxide) impregnated in the porous media. The porous hybrid media may advantageously be prepared at low temperature (e.g., room temperature).
1. A method of preparing a porous hybrid media, the method comprising:
contacting porous media with an aqueous solution comprising aluminum ions to yield a mixture;
adjusting a pH of the mixture to form a floc comprising aluminum hydroxide;
removing liquid from the mixture to yield aluminum hydroxide-containing porous media;
contacting the aluminum hydroxide-containing porous media with a reducing agent to yield a porous hybrid media comprising aluminum hydr(oxide) impregnated in the porous media.
2. The method of claim 1 , wherein the aluminum ions are derived from aluminum chloride.
3. The method of claim 1 , wherein the reducing agent comprises borohydride.
4. The method of claim 1 , wherein adjusting the pH of the mixture comprises increasing the pH of the mixture to less than 6.
5. The method of claim 4 , wherein adjusting the pH of the mixture further comprises, after increasing the pH of the mixture to less than 6, increasing the pH of the mixture to greater than 6 and less than 8.
6. The method of claim 1 , wherein preparing the porous hybrid media occurs at room temperature or a temperature less than about 40° C.
7. The method of claim 1 , the porous media comprises strong base ion-exchange media.
8. The method of claim 1 , wherein an aluminum content of the porous hybrid media is between 3 wt % and 4 wt %.
9. The method of claim 1 , wherein the aluminum hydr(oxide) comprises γ-Al 2 O 3 , amorphous Al 2 O 3 , amorphous AlO(OH), or a combination thereof.