2,956
edits
Archive:000/Hydrogen gas: Difference between revisions
→Platinum-group metals
(Restructured the page) |
|||
| Line 52: | Line 52: | ||
===Platinum-group metals=== | ===Platinum-group metals=== | ||
{{sum|Possible problem}} | {{sum|Possible problem}} | ||
Both '''electrolysis''' and '''fuel cells''' need platinum-group metals (PGMs): | |||
* '''[platinum, palladium, rhodium, ruthenium, iridium, osmium]''' | |||
** Any of these metals will do, but all of them are extremely scarce (even more than gold), with platinum & palladium being the most available. | |||
** These metals serve as ''catalysts'' in the reactions. They are not used up, but they need to ''be there'', in a thin layer plated onto the electrodes. | |||
{{minor|Note: It ''is'' possible to build fuel cells and electrolysis systems without PGMs, but the energy-efficiency is much lower.{{qn}} There are scientists trying to overcome this,<sup>[LINKS needed]</sup> but there's no guarantee that it will be viable in the near future.}} | |||
====How much would be needed, if hydrogen were scaled up?==== | |||
<tab name="General principles"> | |||
{{minor|The mass of PGMs needed is proportional to ''peak power'':}} | |||
* For electrolysis systems, the maximum '''rate of hydrogen production''' {{light|is limited by the amount of PGMs}}. | |||
* For fuel cell vehicles, the '''horsepower''' {{light|is limited by the amount of PGMs}}. | |||
** {{minor|But the vehicle can still achieve ''short bursts'' of higher horsepower if there's a battery or supercapacitor in parallel with the fuel cell.}} | |||
</tab> | |||
<tabs><tab name="Estimate #1"> | |||
Suppose, | |||
* that all of today's [[energy demand]] were to be met using hydrogen gas | |||
* that all hydrogen gas is produced using [[wind]] power (or something with the same [[capacity factor]] as wind) | |||
{{empty}} | {{empty}} | ||
</tab></tabs> | |||
<!-- TODO: Uncomment this when done writing about PGMs above (a more immediate and important mention that should be on here first) | <!-- TODO: Uncomment this when done writing about PGMs above (a more immediate and important mention that should be on here first) | ||