How to increase alumina washcoat on ceramic substrate

Hi,

I'm trying to increase alumina washcoat amount on ceramic substrate, but everytime I failed because of low adhesion ability. Can you tell me the best procedure for alumina washcoating. It's similar 3 way catalyst system.

Thanks in advance.

Reply to
Do-Woan Kim
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Could we get more info, Please?

What is the substrate? How are you preparing it? Why not solid alumina?

tom

Reply to
Tom Walz

Hi, Tom. Thanks for response.

Substrate is commercial cordierite honeycomb with 400 cpsi. I tried with 50% solid percent gamma alumina slurry(pH=3.5), after dipping substrate on slurry for 1 minute, finally air blowing.. Actually am thinking this solid % of 50% is too high.. I don't understanding last question of solid alumina, I'm using gamma alumina as solid powder and ball milling was applied to adjust to particle size of 2~10 nm size.

Do-Woan Kim

Reply to
Do-Woan Kim

2-10 nm? Did you mean 2-10 microns? Getting 2-10nm from ball milling is quite a trick. There are a variety of green binders you can use if your doing some post firing. There are also a variety of aluminas in the nm size you can use in a small percentage as a binder. If your getting 50% solids and low viscosity from 2-10 nm particle size - that's unusual. What's the surface area of the alumina?

Gregg

Reply to
Gregg

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