UC Berkeley researchers have developed a gelatin-based catalyst that generates hydrogen fuel from water just as efficiently as platinum.
The cheap and effective catalyst has proven to match platinum – which is currently not only the best, but also most expensive water-splitting catalyst out on the market today.
Composed of nanometer-thin sheets of metal carbide, the catalyst was manufactured using a self-assembly process that relies on a surprising ingredient: Gelatin, or the material that gives Jell-O its jiggle.
“Platinum is expensive, so it would be desirable to find other alternative materials to replace it,” said senior author and mechanical engineering professor Liwei Liny.
“We are actually using something similar to the Jell-O that you can eat as the foundation, and mixing it with some of the abundant earth elements to create an inexpensive new material for important catalytic reactions.”
“The traditional way of using water gas to generate hydrogen still dominates in industry. However, this method produces carbon dioxide as byproduct,” said first author Xining Zang.
“Electrocatalytic hydrogen generation is growing in the past decade, following the global demand to lower emissions. Developing a highly efficient and low-cost catalyst for electrohydrolysis will bring profound technical, economical and societal benefit.”
To create their catalyst, the researchers followed a recipe nearly as simple as making Jell-O from a box.
They mixed gelatin and a metal ion – either molybdenum, tungsten or cobalt – with water, and then let the mixture dry.
Heating the mixture to 600 degrees Celsius triggered the metal ion to react with the carbon atoms in the gelatin, forming large, nanometer-thin sheets of metal carbide.
Upon testing their recipe, the researchers noticed that molybdenum carbide split water the most efficiently, followed by tungsten carbide and then cobalt carbide, which didn’t form thin layers as well as the other two.
Mixing molybdenum ions with a small amount of cobalt boosted the performance even more.
The 2D shape of the catalyst is one of the reasons why it is so successful.
And because it is so easy to make, the recipe could be easily scaled up to produce large quantities of the catalyst, the researchers contend.
Image and content: Xining Zang graphic, copyright Wiley/UC Berkeley