We like the idea of hydrogen fuel cell vehicles which, in themselves, generate water vapor as their only emission. Hydrogen fuel, however, could prove to be a sticking point.
Considering that second point, hydrogen fuel cell vehicle opponents have pointed to hydrogen fuel generation’s fossil-fuel roots as a clear indication that they aren’t viable emissions-free technology. Actually, that’s just one of a number of myths floating around hydrogen fuel cell vehicles, which we covered in a series, starting here. (The rest of the series is here: Fuel Cell Vehicle Myth 2, 3, 4, 5, 6, 7, 8, 9, and 10) Turning our attention specifically to renewable hydrogen fuel generation, however, it’s totally unfair to say that fossil fuels are the only viable source.
The only problem with renewable hydrogen fuel generation has to do with efficiency and cost, particularly with the catalysts required to split hydrogen from oxygen, via electrolysis. True, wind power and solar power may be totally renewable, but a hydrogen fuel generation system connected to it must be able to produce enough fuel for a number of vehicles, which increases the costs associated with it. Some rare-earth and precious-metal catalysts, such as platinum or iridium, are prohibitively expensive, not to mention that they’re also rare in supply. Platinum, for example, is currently worth $1,400/oz ($49.38/g) and iridium is a bargain at $630/oz ($22.22/g). Iron and nickel, on the other hand, are relatively abundant, worth less than 2.8¢/oz (0.01¢/g) and 52.9¢/oz (1.9¢/g), respectively.
Stanford University Professor Hongjie Dai has developed an electrolysis device based on these two cheap and abundant metals that splits water into hydrogen and oxygen. While electrolysis isn’t unheard of, running it off of a single 1.5 V “AAA” battery is practically unheard of. Using a new nickel-metal / nickel-oxide electrode combination, researchers under Professor Dai found that it was at least as efficient as platinum. The miniscule costs of the materials, however mean that such electrolysis devices could be scaled to industrial capacity fairly cheaply. Additionally, the low-voltage requirements make renewable hydrogen fuel generation, even by solar power, more viable than ever.
Image © Stanford University