text: how does catalytic decomposition of sulphur compounds work? i distil my own vodka, using a still which is available commercially.   various sulphur compounds give the spirit an off taste, rather like the smell of cabbage cooking, and they must be removed.   until now i've done this with charcoal, but i've just bought a copper catalytic converter which you insert in the outflow of the still.   it's a tangle of thin copper wire like a copper scouring pad.   you're instructed to clean it with water and white vinegar before each use.   what is the chemical reaction that decomposes the sulphur compounds?   what temperature range is needed?   could you get the same result by placing the converter in a bottle of the spirit instead of the vapour coming from the still?   traditional pot stills for making whisky and brandy are made of copper. a couple of links  http://aiche.confex.com/aiche/2005/techprogram/p18146.htm  http://www.freepatentsonline.com/4544461.html  i believe your system is not catalytic and is just the reaction of the copper with hydrogen sulfide to get copper sulfide which you then wash off.