On Mon, 2002-10-28 at 21:54, Pierce Nichols wrote: > All of the catalysts for peroxide that I have heard > tested or floated in any way are transition metals or their oxides. > Anecdotal evidences (such as the requirement for 'burning in' a silver > pack) indicates that it's the oxides that have the real catalytic action.
What if, in general, it's *only* the oxides of these metals that are catalytic and not the metals themselves at all? What if silver is only so good because its oxide is so tenacious? If this is the case, then the process would be clear: find a transition metal with a tenacious oxide that can stand high temperature... this would be what you call "convenent properties." Even if they don't *form* their oxides easily, they probably will form oxides at high temperatures in highly oxidizing environments. Even stainless will, but from what you're saying it sounds like it would probably be sacrificial. Of course, the damned chamber is stainless, but clearly it doesn't have the kind of surface area we need. I think it's time to do some experimenting. Perhaps we should make up a catalyst pack from plain ol' stainless and play around with it? How about nickel? We can get nickel foam pretty easily, and the nickel's darned durable. The next question is the best way to heat the pack. I think that you're right about no-preheat-necessary being a snipe hunt. I'd rather use a preheater and have a wide class of materials available to me than no preheater and a narrow (possibly empty) class of materials. Even if we do find something, it's going to have a lower limit for temperature, and it seems like stuff that's good at low temperatures may not be good at high temperatures. As I said, even silver is a crappy catalyst when cold, and even though it works well at the range of temperatures we work at, it goes away when you heat it too much, i.e. with 99% peroxide. And of course the catalyst spends most of its time at very high temperatures, not at the low starting temperatures, though it's just as vital in both conditions, so preheating makes more and more sense the more I type. I'm going to bed.
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