Well I had a quick look at the internet and came up with the figure of 1 gram per kW for the fuel cell.
A catalytic converter has around 2 to 7 grams. The larger the engine, the bigger it is, so no definitive answer to that, so I shall work on 1 gram per 50 kW of engine power. Seems reasonable.
Now on DriveTribe, we all dream that our cars have at a bare minimum 500 horse power, which is 375 kW ish.
The reality is that most of us drive pathetic 125 HP cars, so that is 94 kW.
So I shall work on 100 kW engines and see how they compare.
Almost how it works, without all the real science
I have to make assumptions that each vehicle can do 150,000 miles before the fuel cell or the catalytic converter needs changing. This may, or may not be correct, but if you own a calculator you can change the numbers to suit what you wish to say.
So initially, a petrol engined car needs 3 grams of platinum and the hydrogen powered one needs 100 grams. Quite a difference.
But does that difference actually matter if we have lots of platinum. So let’s look at the known resources, as that is what matter more than the reserves.
The global resource for platinum is around 70,000 metric tonnes. That is quite a lot.
Full of energy
Now let us say that we can produce 20 million cars a year, a quick bit of arithmetic shows that we could produce 700 million hydrogen fuel cells or 2.33 billion catalytic converters.
So it seems to me that there is no lack of platinum.
So how much difference would it make on carbon dioxide levels? Well not a lot for an internal combustion engine. One of the reasons for using a platinum catalytic converter is to turn unburnt hydrocarbon fuels into carbon dioxide and water vapour. So in the scheme of things this makes no difference. Now a half decent car will convert gasoline into about 140 grams of carbon dioxide for every mile travelled.
A fuel cell car, while not having any tail pipe emissions, still uses energy from somewhere.
If I assume the delivered energy has 200 grams of carbon dioxide for every kWh used to convert water into hydrogen, and using Honda’s claim that they can convert at 64% efficiency, and assuming that the kWh per mile is the same as a decent EV at around 0.22 kWh/mile, then that works out just shy of 70 grams carbon dioxide per mile.
So that is about half what a decent ICE car does.
So to draw a conclusion, as there is no lack of platinum, electricity can be cleaned up still more, but there is limited scope to clean up gasoline engines.
Get a hydrogen fuel cell car and half your carbon dioxide emissions.
Or get a battery electric vehicle and nearly half then again to 45 grams per mile.
Batteries in my boot