Green hydrogen from more affordable water

May 31. (EUROPE PRESS) –

The US Department of Energy’s Argonne National Laboratory has developed a low-cost catalyst for a process that produces clean hydrogen starting from the water.

Clean hydrogen could not only power vehicles without polluting emissions, but would also help decarbonise industrial processes.

“When using the cobalt based catalyst prepared with our method, the main cost bottleneck of producing clean hydrogen in an electrolyser could be removed,” explains it’s a statement Di-Jia Liu, a senior chemist at Argonne.

Proton Exchange Membrane (PEM) electrolyzers represent a new generation of technology for this process. They can split water into hydrogen and oxygen most efficiently at near room temperature. Reduced power demand makes them an option ideal for producing clean hydrogen by using renewable but intermittent sources such as solar and wind.

This electrolyser works with separate catalysts for each of its electrodes (cathode and anode). The cathode catalyst produces hydrogen, while the anode catalyst forms oxygen. One problem is that the anode catalyst uses iridium, which has a current market price of around $5,000 per ounce (28 grams). The lack of supply and high cost of iridium represent a significant barrier to the widespread adoption of PEM electrolysers.

The main ingredient in the new catalyst is cobalt, which is substantially cheaper than iridium. “We seek to develop a low-cost anode catalyst in a PEM electrolyzer that generates hydrogen at a high yield with minimal power consumption,” Liu said. “By using the cobalt-based catalyst prepared with our method, the main cost bottleneck of producing clean hydrogen in an electrolyser could be removed“.

Giner Inc., a firm that markets electrolyzers and fuel cells, evaluated the new catalyst using its PEM electrolyzer test stations under industrial operating conditions. Performance and durability far exceeded competitive catalysts.

To further advance catalyst performance it is important to understand the reaction mechanism on an atomic scale under electrolyser operating conditions. The team deciphered the critical structural changes that occur in the catalyst under operating conditions using X-ray analysis at the Advanced Photon Source (APS) at Argonne. They also identified key features of the catalyst using electron microscopy at Sandia Labs and Argonne’s Center for Nanoscale Materials (CNM).

“We took images of the atomic structure on the surface of the new catalyst at various stages of preparation.said Jianguo Wen, a materials scientist at Argonne.

Additionally, computational modeling at Berkeley Lab revealed important information about catalyst durability under reaction conditions.

GREEN HYDROGEN AT ONE DOLLAR PER KILO

The team’s achievement is a step forward in DOE’s hydrogen-powered Earthshot initiative, which mimics the “Moon Shot” of the 1960s American space program. His ambitious goal is to reduce the cost of green hydrogen production to one dollar per kilogram in a decade.. The production of green hydrogen at that cost could reshape the nation’s economy. Applications include electrical grid, manufacturing, transportation, and residential and commercial heating.

“More generally, our results set out a promising path to replace catalysts made of expensive precious metals with elements that are much less expensive and more abundant,” Liu said.

This research was published in Science.