Prof Richard Haverkamp, of Massey University, explains why gold is a better catalyst than platinum for producing hydrogen from methane.
DR RICHARD HAVERKAMP
One of the more promising types of fuel cells is a hydrogen fuel cell, that’s the one that people have got to work the best. But there’s one catch to it that people gloss over and that is that you need very pure hydrogen. Most of the hydrogen is currently made by natural gas reforming. So you take natural gas which is methane from a natural gas and you react it with water and you make hydrogen. Now that is the theory but there is always a little bit of carbon monoxide in it, and the trouble with that is is that carbon monoxide is a poison for the normal catalyst that are used for hydrogen fuel cells. So hydrogen fuel cells normally have a platinum based catalyst and as soon as you put a bit of carbon monoxide on it, it starts to kill that catalyst and eventually the fuel cell will stop working. So you have to have very clean hydrogen and its not that easy to get rid of all of that carbon monoxide. So that’s where gold is got a lot of interest as a catalyst, because gold is not bothered by carbon monoxide. It just laughs by carbon monoxide, it doesn't get poisoned by it. So gold would be a very good catalyst for a fuel cell where there is a risk that some carbon monoxide is in it.