I am trying to better understand the chemistry behind how these small fuel filled hand warmers work. Typically they are filled with lighter fluid, which vaporizes through a cotton barrier and comes in contact with a platinum based catalyst that has been heated (? Ignited). You can control the heat output to some degree by varying the amount of oxygen available to the system. This would suggest to me a combustion reaction, but there is no flame, not when you heat the catalyst or as it reaches maximum temperature. You can see a very slight redness to the catalyst at night but otherwise nothing. So much of the information available out these small devices suggests that it is “not burning the lighter fluid” - the vapors from the butane (generally the fuel used, but not always) are simply “reacting” with the catalyst in an oxygen rich exothermic reaction that releases heat, warming up the device. To me this certainly sounds like combustion, but perhaps I am missing a different type of chemical reaction and taking place and simply don’t understand. I would really appreciate any/all insight from someone who understands these devices.
