In grade school, I came across a brief mention in a 5th grade textbook of
an igniter that was used in 1930s gas stoves in place of a pilot light.
The device consisted of a thin Platinum wire located in the burner area.
When natural gas, containing a high concentration of Hydrogen, passed over
the wire, it got hot enough to ignite the gas stove. This process was
called adsorption.

In subsequent classes up to lower division chemistry and upper division
physics, there was no mention of this phenom and my instructors hadn't a
clue as to what I was talking about. (A not - uncommon reaction )

A Google search recently showed that this phenomenon is apparently a
latter-day embodiment of on earlier device -- by Dobereiner -- one of the
"founders" of the Periodic table -- that used hydrogen and air mixed with
platinum as a cigar lighter. About 20,000 of these devices were sold in
the 19th century!

Apparently, palladium also has the same characteristic.

I have been unsuccesful in finding any scientific explanation of this
phenomenon. It is apparently NOT catylitic since -- in pure hydrogen --
there is no chemical reaction.

The question: Is the heat and light that is emitted due to collision
between hydrogen atoms and platinum/palladium, or is some other phenomenon
involved? How do we know?

Just a little brain teaser for the "dog days" of summer

Bill Miller

I have been unsuccesful in finding any scientific explanation of this
phenomenon. It is apparently NOT catylitic since -- in pure hydrogen --
there is no chemical reaction.

yeah, its not a very well known phenomenon... only 14,600 hits on google
for 'adsorption platinum igniter' including a couple patents and a 1962
project report from nasa.

"Bill Miller" <billmillerkt4ye@worldnet.att.net> wrote in message
news:E5Hsi.16888$ax1.6849@bgtnsc05-news.ops.worldnet.att.net...
In grade school, I came across a brief mention in a 5th grade textbook of
an igniter that was used in 1930s gas stoves in place of a pilot light.
The device consisted of a thin Platinum wire located in the burner area.
When natural gas, containing a high concentration of Hydrogen, passed
over the wire, it got hot enough to ignite the gas stove. This process
was called adsorption.

In subsequent classes up to lower division chemistry and upper division
physics, there was no mention of this phenom and my instructors hadn't a
clue as to what I was talking about. (A not - uncommon reaction )

A Google search recently showed that this phenomenon is apparently a
latter-day embodiment of on earlier device -- by Dobereiner -- one of the
"founders" of the Periodic table -- that used hydrogen and air mixed with
platinum as a cigar lighter. About 20,000 of these devices were sold in
the 19th century!

Apparently, palladium also has the same characteristic.

I have been unsuccesful in finding any scientific explanation of this
phenomenon. It is apparently NOT catylitic since -- in pure hydrogen --
there is no chemical reaction.

The question: Is the heat and light that is emitted due to collision
between hydrogen atoms and platinum/palladium, or is some other
phenomenon involved? How do we know?

Just a little brain teaser for the "dog days" of summer

Bill Miller

14,600 queries ain't much on Google. But thanks for a good set of search

"Bill Miller" <billmillerkt4ye@worldnet.att.net> wrote
news:E5Hsi.16888$ax1.6849@bgtnsc05-news.ops.worldnet.att.net...

I have been unsuccesful in finding any scientific explanation of this
phenomenon. It is apparently NOT catylitic since -- in pure hydrogen --
there is no chemical reaction.

"
Catalysis. The term was coined by Swedish chemist Jons Jacob Berzelius.
The discovery, however, belongs to Johann Wolfgang Dobereiner, who in 1823
discovered the catalytic action of platinum.

His work focused on the action of platinum black on hydrogen. In his
experiments, finely divided platinum powder ignited a stream of hydrogen
directed at it, turning the platinum white-hot. From this discovery
evolved the pneumatic gas lighter, or Dobereinersche Feuerzeug. Hydrogen
gas generated from zinc and sulfuric acid would stream through a narrow
opening toward a holder in which a platinum sponge was suspended on a thin
platinum wire, igniting it. The platinum was reactivated through heating.
By 1828, some 20,000 lighters were in use in Germany and England, some of
them highly decorated objets d'art and collectors' items"

H2 transfer into 2H. It is the chemical reaction.

S*

OK... but Hydrogen, in a gaseous state is just H. I see no chemical
reaction here at all.

Also, WHY does the mere presence of Pt in Hydrogen lead to an exothermal
phenomenon? In other words, where does the heat (and light!) come from?

"Bill Miller" <billmillerkt4ye@worldnet.att.net> wrote
news:yf4ti.397849$p47.313526@bgtnsc04-news.ops.worldnet.att.net...


OK... but Hydrogen, in a gaseous state is just H. I see no chemical
reaction here at all.

Hydrogen, in a gaseous state is H2 like N2, O2 and so on. The rest of
necessary information you can pick up from:

http://en.wikipedia.org/wiki/Catalyst

Also, WHY does the mere presence of Pt in Hydrogen lead to an exothermal
phenomenon? In other words, where does the heat (and light!) come from?

2H2 + O2 = 2H2O
The mere presence of Pt makes that this reaction starts at room
temperature.
S*

"Szczepan Bia³ek" <sz.bialek@wp.pl> wrote in message
news:f92n68$faq$1@node1.news.atman.pl...

"Bill Miller" <billmillerkt4ye@worldnet.att.net> wrote
news:yf4ti.397849$p47.313526@bgtnsc04-news.ops.worldnet.att.net...


OK... but Hydrogen, in a gaseous state is just H. I see no chemical
reaction here at all.

Hydrogen, in a gaseous state is H2 like N2, O2 and so on. The rest of
necessary information you can pick up from:

http://en.wikipedia.org/wiki/Catalyst

Also, WHY does the mere presence of Pt in Hydrogen lead to an exothermal
phenomenon? In other words, where does the heat (and light!) come from?

2H2 + O2 = 2H2O
The mere presence of Pt makes that this reaction starts at room
temperature.
S*

Hello S*...

Thanks for the Wikipedia suggestion

but this does not answer the question that I am asking. And Dave's multiple
hits on the Google search for "Adsorption, Platinum Igniter" are mostly
"partial" hits that do not deal with my question. Google Scholar provides
some peer-reviewed work but no apparent answer to the question I am asking.

I am not inquiring about the Catalytic conversion of 2H2 and O2 into
Water, nor what happens when Pt is mixed with a variety of gases that are
rich in H2. This is a well known (if not well-understood) phenomenon.

I am interested in what happens when Pt is in the presence of ONLY
Hydrogen.

When Pt is immersed in H2 (only), it appears that the Pt gets Very Hot.

I am interested in what is going on to cause Pt to emit IR and Visible
light EM radiation when in the presence of hydrogen gas and ONLY hydrogen
gass.

No catalytic conversion. No chemical reaction. Just Platinum and Hydrogen.

This *must* have been studied,

but all I have been able to find is anecdotal information: (it gets hot)

or discussions of how this phenomenon can be used to light cigars, ignte
various gases that contain hydrogen, and (occasionally) blow things up.

Sorry but after yours "Hydrogen, in a gaseous state is just H" I assumed
that it will be helpful. This is shorter:
http://www.chem.umn.edu/services/lecturedemo/info/hydrogen_and_platinum.html

When Pt is immersed in H2 (only), it appears that the Pt gets Very Hot.

That " it appears". Where can we read about this? H and Pt make something
like alloy. May be that heat of solution is high.

I am interested in what is going on to cause Pt to emit IR and Visible
light EM radiation when in the presence of hydrogen gas and ONLY hydrogen
gas.

No catalytic conversion. No chemical reaction. Just Platinum and
Hydrogen.

This *must* have been studied,

Before study "must* have been done a description of the phenomenon. Can
anybody help?

but all I have been able to find is anecdotal information: (it gets hot)

"hot" is closee to warm, not to Visible light EM

or discussions of how this phenomenon can be used to light cigars, ignte
various gases that contain hydrogen, and (occasionally) blow things up.

It seems that there was the oxygen.
S*

Snip
Sorry but after yours "Hydrogen, in a gaseous state is just H" I assumed
that it will be helpful. This is shorter:
http://www.chem.umn.edu/services/lecturedemo/info/hydrogen_and_platinum.html


Interesting but again this shows a chemical reaction. I'm interested in an
exothermal non-chemical event.

snip

When Pt is immersed in H2 (only), it appears that the Pt gets Very Hot.

That " it appears". Where can we read about this? H and Pt make
something like alloy. May be that heat of solution is high.

Here is a quote from one of the first websites I looked at,
http://www.americanscientist.org/template/AssetDetail/assetid/27722?&print=yes

"And Döbereiner observed in 1823 that when platinum metal (in a finely
dispersed form called platinum sponge), was exposed to hydrogen, much heat
was generated. The platinum (Pt) in fact glowed red- to white-hot."

Sounds like Döbereiner (and those that copied the American Scientist
article may have gotten it wrong!

I am interested in what happens when Pt is in the presence of ONLY
Hydrogen.

When Pt is immersed in H2 (only), it appears that the Pt gets Very Hot. I
am interested in what is going on to cause Pt to emit IR and Visible light
EM radiation when in the presence of hydrogen gas and ONLY hydrogen gass.

No catalytic conversion. No chemical reaction. Just Platinum and Hydrogen.

Interesting but again this shows a chemical reaction. I'm interested in an
exothermal non-chemical event.

"And Döbereiner observed in 1823 that when platinum metal (in a finely
dispersed form called platinum sponge), was exposed to hydrogen, much heat
was generated. The platinum (Pt) in fact glowed red- to white-hot."

What I am beginning to wonder is if it is the adsorption that is causing the
heat (as implied above) or is it the catalytic (and exothermic) reaction
that is the heat source. I am beginning to strongly suspect the latter. None
of the discussions that I have found re adsorption and different metals make
mention of heat.