> the catalyst itself must be 're-energized' or replaced
That does not exactly fit the definition of a catalyst, to put it politely.
Honest question: are you trolling, or do you simply need a refresher on the basic principles of thermodynamics?
That does not exactly fit the definition of a catalyst, to put it politely.
Honest question: are you trolling, or do you simply need a refresher on the basic principles of thermodynamics?
Some catalysts do get "degraded" over time and need to be regenerated. Look up palladium sintering or zeolite coking. The catalyst itself is not "damaged" but by catalyzing a reaction, its physical shape is altered (get clogged or fused together) which reduce its effectiveness. These can be regenerated by burning off the clogging or heating them up.
And if you get into the enzymes, which are biological catalysts, they are even more likely to degrade and need to be replaced.
Don't try to be smart by insulting others when you yourself are not an expert.
Maybe that's now what was meant, maybe they were indeed talking about the catalyst being degraded. But then it's a bit weird to talk about "re-energizing", and more importantly, that still doesn't the main question: what is the energy source?
Am I too hostile towards claims that energy can be made out of nothing? Maybe. I know I don't feel guilty when exposing fraudulent claims.
That is NOT a catalyst, as roelschroeven correctly commented.
Otherwise a rechargeable battery would be a "catalyst" because it too needs to be re-energized or replaced.
What a catalyst does is lower the activation barrier between two states, without providing net energy. Getting H2 from H2O, i.e. electrolysis, requires adding energy. We know this because fuel cells work in the other direction to produce power, and entropy always increases.
If oxygen is bound to the aluminum oxide, and requires energy to remove, it is not a catalyst.
Why are you capitalizing Aluminum and Oxygen?
catalyst [2] - "a substance that enables a chemical reaction to proceed at a usually faster rate or under different conditions (as at a lower temperature) than otherwise possible"
1. https://www.esafety.gov.au/young-people/trolling#:~:text=Tro....
2. https://www.merriam-webster.com/dictionary/catalyst
I guess I'm missing something. The poster asked a question, I provided an honest response based on my professional experience. I believe this is in the positive collaborarive spirit of HN. I'm just trying to contribute information that may not be readily available elsewhere.
Cheers.
To split water into hydrogen and oxygen, you need to add energy. It's very well possible that a catalyst can make the process more efficient than simple electrolysis, it can't change the fundamental fact that energy needs to be added for the reaction to occur. A catalyst will decrease the required activation energy, but not the total energy balance.
When you say that the catalyst itself must be 're-energized' or replaced, it sounds like the catalyst is the source of energy. Maybe that's not correct, but then the question remains: where does the energy come from?