PGM chemistry is not fun and games when you really step into it
Some advice for the future:
1. Spend at least hour or two researching relevant forums and advice/articles/other literature/etc. before attempting ANY kind of chemistry which is new to you. Or ask here on the forum if this hour search won´t give any good results. Get familiar with dangers arising from it, look up not only substrates/chemicals used, but also all possible products of reaction. This can literally save your life. As professional organic chemist with relatively rich experience also with refining, I can say this routine is well worth it. And if it don´t save your health or life, it saves a lot of time.
It will be foolish to think that nobody ever tried the same procedure you attempted. Almost everything in simple aqueous inorganic chemistry was already done in the past (either by professionals and amateurs) and most of the times the information about it is on the internet.
2. Bleach is a commercial product. And as with all commercial products, the exact composition is proprietary. Many producers add additives into regular hypochlorite bleaches to cover the noxious odor or colourants, some even detergents. This can interfere with the reaction.
Also, my main concern will be if there was the hypochlorite itself. Bleach decompose over time by itself, and it can be well possible that your was already "dead". Always look to the manufacture date on the package and ensure it wasn´t stored for too long, espetially in summer months. Retailers have it placed on the shelf, or somewhere in the storage at the back of the supermarket, where it does not have AC in the summer - and whoopsie, you purchase "brand new" bottle claiming 5% potency, but in reality there is like 1-2 %. Happens a lot. Be aware of that.
3. Leaching out honeycomb from cats or leaching MLCCs is the worst procedure you can do to recover PGM´s from this ceramic type of matrix. There is one very lenghty thread where I, kurtak and many others tried to help to resolve the situation where one of our members started leaching several kilos of crushed MLCC´s in acid. It was very unplesant experience, mainly for him.
This is that thing about research - if you looked and thoroughly searched the forum, you will find this info in like 90% of the threads issuing "cats" or "MLCCs". But you will now know for the future
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As it is said "the damage was already done"
But positive thing is - you cannot chemically destroy the very elements. If you don´t discard the solids or leachate, values are still there. Good thing is that you see red colour. Now you will need to stir it occasionally for some week or two and adding portions of bleach from time to time to assure high redox. Then proceed as sreetips in his video about wet cat leaching process.