| Pages:
1
2 |
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
the density is not too high
about 300ma/cm^2
|
|
|
Xenoid
National Hazard
Posts: 775
Registered: 14-6-2007
Location: Springs Junction, New Zealand
Member Is Offline
Mood: Comfortably Numb
|
|
Well I think that is very high!
I don't even run Pt that high, but I'm pretty conservative on this aspect!
None of my homemade "oxide" based anodes seems particularly stable above 100mA/cm^2. I would suggest you lower the current density by at least half,
see what happens!
|
|
|
chloric1
International Hazard
Posts: 1147
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
hashashan- You may have to run slightly below 100mA/cm2 given what dann2 experienced in trying his DTO anode. Apparenty the lithium chloride is more
erosive towards anodes than its sodium counterpart.
Fellow molecular manipulator
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
Well lowered it to about 150ma/cm2 ..... Ill lower it to 100 just in case and let it run for a day
I don't know ... I usually run the PbO2 at 300-500 with NaCl and there is only slight erosion ... not too much about half a gram per 350g of NaCl
But with the LiCl I got a really brown solution in only half an hour ... I never saw that dark solution with the NaCl .. not even after a week at
400ma/cm2
Anyone tried Barium Chloride?
Update:
Setting it to 150mA/cm2 helped a lot.
after 12 hours there is some erosion but not as near as it was at 300mA/cm.
I would go down to 100mA/cm2 but it will take for ever to finishe the process.
It will take 20 days only for the chlorate, supposing that the cell efficiency is 50%
[Edited on 28-1-2008 by hashashan]
[Edited on 29-1-2008 by hashashan]
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
Well its been 20 days already
no perchlorate has yet formed ... Is it possible that a cell with a conc. solution and magnetic stirring will be less efficient then 50%???
anyone has any ideas why is it taking so long?
|
|
|
dann2
International Hazard
Posts: 1523
Registered: 31-1-2007
Member Is Offline
Mood: No Mood
|
|
Hello Hashashan,
I can't figure out from the posts how much LiCl you have in your cell.
50g per 100ml? How big is the cell 600ml?.
The efficiency may be below 50%.
Keep going.
At least when you do get to the Perchlorate stage things will finish up soon enough.
Dann2
|
|
|
Xenoid
National Hazard
Posts: 775
Registered: 14-6-2007
Location: Springs Junction, New Zealand
Member Is Offline
Mood: Comfortably Numb
|
|
| Quote: | Originally posted by hashashan
no perchlorate has yet formed ... |
Hashashan - have you made sure the (non)perchlorate solution from the cell was cool. If you remember, I found the Methylene Blue test doesn't work at
temperatures above about 35 oC.
Methylene Blue Testing: http://www.sciencemadness.org/talk/viewthread.php?tid=9783&a...
Dann2 has also verified this. Make sure you cool your solution to, say, about 15 oC. first before doing the test!
|
|
|
tentacles
Hazard to Others
Posts: 191
Registered: 11-11-2007
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by hashashan
Well its been 20 days already
no perchlorate has yet formed ... Is it possible that a cell with a conc. solution and magnetic stirring will be less efficient then 50%???
anyone has any ideas why is it taking so long? |
I did read somewhere that stirring the cell contents was detrimental to efficiency. One of those older JES papers. It was significant in some of their
tests - as much as 30% in cases were previously high effs were achieved. In low eff tests the difference was like 10-15%.
[Edited on 17-2-2008 by tentacles]
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
Its a 6-7 mol cell ... the 6-7 is due to the fact that I added more lithium chloride as the solution evaporated. the volume is 1 liter
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
ARGGGGGGGGGGGG
still no perchlorate . It really starts to piss me off.
I increased the voltage and now the cell is running at about 7 amps. that is about 250ma/cm2. hopefully that will help.
As the chloride level decreased I cant see any signs of erosion even at that current density(just like with Na).
@Xenoid : my solution temp. is quite low as it is ... about 20 degrees. Also when the perchlorate levels get high then the test work even in higher
temperature.
|
|
|
chloric1
International Hazard
Posts: 1147
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
not a good sign hashhashen, it has been 30 days I believe . The ions are conspiring against you. Did you get perchlorate when you used NaCl? I
don't remember if you added a catalyst like a fluoride or a persulfate. Are you getting high chlorate? IF so then maybe your chlorate is being
reduced at the cathode. Don't know but trying using a bigger cathode.
Fellow molecular manipulator
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
I got slight signs f perch 
and my cathode is twice the size of the anode
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
