一本教會你“做對”題的6級閱讀書 day4 passage7
Passage 7 Cheap Catalyst Can Make and Break Hydrogen 069
一種新的催化劑 《紐約時報》2009-12-7
[00:02]A cheap catalyst can both generate hydrogen and release energy from it.
[00:08]The new material could be a breakthrough
[00:12]that will allow the unpredictable energy flows from wind
[00:17]and solar farms to be stored.
[00:20]As nations attempt to put their energy consumption in order,
[00:25]the need for better ways to store electrical power is becoming apparent:
[00:33]wind and solar power installations don't always provide power
[00:39]when it's most needed. Batteries are one option -
[00:43]although they'll have to improve before they are practical
[00:48]for large-scale storage - but another is converting excess electricity
[00:55]into hydrogen and feeding it through a fuel cell later to generate electricity.
[01:04]Now Vincent Artero at Joseph Fourier University in Grenoble,
[01:10]France, and colleagues have shown
[01:13]that a cheap catalyst could be used to both generate hydrogen to store energy,
[01:21]and also to consume it to extract stored power.
[01:27]Until now, almost all hydrogen-generating catalysts
[01:33]have been made with the expensive metal platinum,
[01:37]making scaling up their use impractical.
[01:43]free catalyst for hydrogen formation was developed in 2006,
[01:50]but it required water-free conditions that were incompatible
[01:56]with conventional methods of making the gas.
[01:58]Artero and his colleagues have solved that problem,
[02:06]coating the platinum-free catalyst in a membrane
[02:10]that lets hydrogen ions reach the catalyst,
[02:14]but not water molecules. The team attached the catalytic molecules
[02:21]to a carbon electrode and sealed it in the waterproof membrane.
[02:27]Then they ran an electric current through the electrode
[02:33]and dipped it into dilute sulphuric acid.
[02:37]They found that hydrogen ions from the watery acid solution travelled
[02:44]through the membrane to the catalyst,
[02:47]where they picked up electrons from the circuit to become hydrogen gas.
[02:54]The team also found that the new design can work in reverse,
[03:01]to split up gaseous hydrogen into ions,
[03:05]and release electrons to provide power.
[03:09]Earlier this year Fraser Armstrong's team at the University of Oxford
[03:17]showed how bacterial enzyme could perform a similar role.
[03:24]Some people think such enzymes will ultimately provide the best way
[03:26]to make hydrogen. "But their production can hardly be scaled up,
[03:26]and the enzymes require special conditions in terms of humidity,
[03:45]pH and temperature," says Artero,
[03:49]who thinks artificial catalysts will probably be the first
[03:54]to enable wide-scale use of hydrogen to store energy.
