Penn State University researchers have recently demonstrated a system that produces hydrogen from water. Nothing fancy so far. What’s interesting is that they use salt water, tap water, bacteria and membranes to make the process self-powered.
Unlike the experiments performed so far, where bacteria inside watery solutions could produce hydrogen only in the presence of outside electricity, the device invented by the PSU researchers uses a process called “reverse electrodialysis” to create electricity inside a microbial fuel cell from the difference in salinity between the two water solutions.
“There are bacteria that occur naturally in the environment that are able to release electrons outside of the cell, so they can actually produce electricity as they are breaking down organic matter,” explained co-author Bruce Logan, from Pennsylvania State University, US.
“All we need to do is add some fresh water and some salt water and some membranes, and the electrical potential that is there can provide that power,” he also said, referring to the innovative system that makes the fuel cell self-sustaining.
“In a way it is a little like solar power. We know we can convert solar energy into electricity but it has taken many years to lower the cost.”
Currently, the demo system used by Logan and his colleagues is too expensive for commercialization. One of the reasons why it is so expensive is that they used platinum (Pt). They nevertheless tested the process with a cheap non-precious metal catalyst (MoS2) and though they got a lower hydrogen output, the results have been satisfying.
More technological details have been published in the Proceedings of the National Academy of Sciences.