Honeycomb air filter and methods thereof

1. An air filter, comprising:

at least one wall-flow honeycomb particulate filter having at least one coat on at least a portion of an interior surface of the at least one wall-flow honeycomb particulate filter, the at least one coat comprising a sorbent and a Pt/TiO 2 catalyst, wherein the sorbent forms islands or clusters dispersed within pores of the at least one wall-flow honeycomb particulate filter and the Pt/TiO 2 catalyst forms separate islands or clusters that are dispersed within the pores of the at least one wall-flow honeycomb particulate filter; and

the air filter, in-use, retains from filtered air a particulate and a volatile organic compound, wherein the volatile organic compound is formaldehyde.

2. The air filter of claim 1 wherein the at least one wall-flow honeycomb particulate filter comprises a first uncoated particulate filter portion, and a second coated filter portion in series and in fluid communication with the first particulate filter portion.

3. The air filter of claim 1 wherein the sorbent comprises at least one of: activated carbon, alumina, zeolite, silica gel, or combinations thereof.

4. The air filter of claim 1 wherein the wall-flow honeycomb particulate filter comprises a ceramic, the filter having:

a % porosity of from 50 to 90 vol %;

a cell density of from 100 to 1600 cpsi; and

at least one dimension and geometry of:

a diameter of from 4 to 20 inches and a length of from 0.5 to 10 inches, for a filter having a circular end face geometry;

a major end face axis of from 4 to 20 inches, a minor end face axis of from 2 to 15 inches, and a length of from 0.5 to 10 inches, for a filter having an oval end face geometry;

a length of from 1 to 20 inches, a width of from 1 to 20 inches, and a height of from 0.5 to 20 inches, for a filter having a rectilinear end face geometry; or combinations thereof.

5. The air filter of claim 1 wherein the walls of the wall-flow honeycomb particulate filter comprise at least one of a ceramic, a glass, a composite, a polymer, a cellulosic, a natural or synthetic fiber, or a combination thereof.

6. The air filter of claim 1 , further comprising two or more of the filters configured in parallel, in series, or combinations thereof.

7. A method of making the air filter of claim 1 , comprising at least one of:

dipping a portion of at least one wall-flow honeycomb particulate filter into a liquid containing at least one sorbent, at least one catalyst, or a combination thereof;

extruding a ceramic batch mixture comprising at least one sorbent, at least one catalyst, or a combination thereof, through a honeycomb forming die;

exposing at least one wall-flow honeycomb particulate filter to a vapor containing at least one sorbent;

exposing at least one wall-flow honeycomb particulate filter to an aerosol containing the at least one sorbent, at least one catalyst, or a combination thereof;

or a combination thereof.

8. The method of claim 7 wherein the dipping coats substantially the entire interior surface of the wall-flow honeycomb particulate filter with the at least one sorbent, at least one catalyst, or a combination thereof.

9. An interior air purification system, comprising:

at least one air handler having a holder for at least one air filter of claim 1 , wherein the air handler directs ambient indoor source air through the at least one air filter and expels filtered air having from 80 to 90% reduction in the particulate content, and from 80 to 90% reduction in the volatile organic compound content, compared to the ambient interior source air.

10. The air purification system of claim 9 wherein the at least one air handler has an air throughput capacity of from 50 m 3 /hr to 1000 m 3 /hr.

11. The air purification system of claim 9 further comprising a housing including two or more of the air filters configured in parallel, in series, or combinations thereof.