Hydrogen, without a shred of doubt, happens to be a promising fuel that can very well drive the global transition to the renewable energy spectrum. But producing hydrogen is at present very much carbon-intensive and, as expected, expensive too.
Water electrolysis happens to be the process of breaking apart the water molecules by way of using electricity. It goes on to offer an ideal process when it comes to producing green hydrogen; however, the catalysts for the process haven’t been understood well at all.
There is a new study that has been rolled out by Northwestern researchers when it comes to the most promising studied catalysts, and that’s iridium-based oxides, which enable the design of a novel catalyst that happens to maintain quite a higher activity, more stability, and, of course, more efficient use of iridium, which could very well make the green hydrogen production much more feasible. The paper, which happened to be published in Natural Catalysis, goes on to identify for the very first time the experimental proof for how the iridium oxide surface happens to change during the process of water electrolysis.
According to Linsey Seitz, the paper’s lead author and also a Northwestern electrochemist, these developments are sure to help bring them much closer to a more sustainable energy future wherein green hydrogen through water electrolysis becomes a reality and a wide rollout of such emerging technologies go on to become more economically as well as technologically feasible.
Seitz happens to be an assistant professor of chemical and biological engineering based out of the McCormick School of Engineering at Northwestern and is also an expert when it comes to renewable energy.
Looking through the findings
Iridium happens to be a rare byproduct of platinum mining and, as a matter of fact, is the only catalyst that is at present viable in terms of green hydrogen production because of the harsh operational conditions due to the reaction. Proton Exchange Membrane water electrolysis is indeed promising as it can go on to run completely on renewable electricity; however, the reaction happens to be in an acidic environment, which itself limits the various kinds of catalysts. The reaction conditions also go on to prominently change the structure of the catalyst materials within their surface, which can be made use of. The reaction conditions also go on to prominently change the structure of the catalyst materials within their surface. Such kinds of recognized catalyst surface structures have been pretty elusive to pinpoint as they change fast when it comes to the process of water electrolysis and can be damaged by way of imaging methods.
A new technique
There is prior research that has gone on to computationally forecast possible connection types that can very well be present on the iridium oxide surfaces but has never been able to offer direct experimental evidence. In the present study, three connection kinds that were described only as amorphous following a catalytic reaction happened to be the most responsible when it came to the stability and activity of the catalysts.
The Seitz team’s workflow went on to significantly decrease the damage from the imaging techniques so as to enable a more precise analysis in terms of structures within complex materials. Firstly, the researchers went on to use electron-based microscopy as well as scattering so as to identify the catalyst surface structure before as well as after the process of water electrolysis. They then went on to confirm results with high-resolution x-ray scattering as well as spectroscopy.
Coming up with more high-performance catalysts
By way of using their own understanding when it comes to iridium, the team was able to design a catalyst by way of using just the paracrystalline structures, which, by the way, were 3-4 times more efficient as compared to other iridium-based catalysts during the process of its very measurement pertaining to the activity. Seitz happens to be also looking forward to applying some new analysis techniques to certain other complex catalyst materials in order to identify active structures. All these fundamental insights are going to be driving the design of high-performance catalysts that can go ahead and optimally make use of precious metals along with critical minerals content, says Seitz.