Researchers Convert Pollution Into Hydrogen

A team of Belgian researchers have developed a device that will remove pollutants from the air and convert them into simple hydrogen — using sunlight, nanoparticles and a photoelectric chemical membrane.

The project was conceived and developed by two sets of researchers working on related issues, says the University of Antwerp’s Sammy Verbruggen. His group, based in Antwerp, has been working on air purification using light and has developed special types of nanomaterials called photocatalysts, which are activated by light and can convert air pollution into less toxic compounds, PRI reported.

A second group, based at the University of Leuven and led by professor Johan Martus, is working with photoelectrochemical cells: membranes that convert water into hydrogen gas that can be used to generate energy.

The new device tries to combine both processes to convert not water, but polluted air into hydrogen, Verbruggen says.

The study used “quite simple, small, organic molecules,” like methanal, acetic acid and ethanol, which can be “quite hazardous to your health,” Verbruggen explains.

Methanal, which is also called formaldehyde, is a known indoor air pollutant that can cause headaches and other physical ailments, including cancer. Acetaldehyde is “the stuff in your brain that gives you a hangover,” Verbruggen says.

The tiny prototype device shows promise, but to make an impact it needs to be vastly scaled up, and this presents a huge challenge, he says.

One avenue is to modify their materials so they can use visible light. Another would be to try to upscale the current design. The first test worked with a membrane with an active area of about 1 square centimeter, compared to other solar-driven technologies like rooftop solar panels.

Even if they do successfully scale up their device, having an impact on a large polluted area may still prove difficult.

“So, if they could use a technology like this one, they can hit two flies at once: They can purify the air, on one hand, and on the other, recover part of the energy that is stored in this polluted air as hydrogen gas, for instance,” Verbruggen says.