How A Cactus Inspired Scientists To Make Cheaper Hydrogen

By Brian Westenhaus - May 18, 2023

• University of Texas scientists have proposed a new material as a catalyst to split water molecules.
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• The durability and unique design of prickly pear cactus in desert environments by adsorbing moisture through its extensive surface and ability to bear fruits at the edges of leaves inspired this study to adopt a similar 3D architecture.
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• Nickel may be a much cheaper catalyst than platinum, but it is not as quick and effective at breaking down water into hydrogen.

Engineers at The University of Texas at El Paso have proposed a low-cost, nickel-based material as a catalyst to help split water more cheaply and efficiently. Their inspiration? A desert succulent known as the prickly pear cactus.

The durability and unique design of prickly pear cactus in desert environments by adsorbing moisture through its extensive surface and ability to bear fruits at the edges of leaves inspired this study to adopt a similar 3D architecture. Image Credit: University of Texas at El Paso. Click the study paper link for more information.

The material is described in a new paper in the journal ACS Applied Materials & Interfaces.

More than 100 years ago, scientists discovered how to turn water into hydrogen gas – a highly desired green energy that’s been nicknamed “the fuel of the future.” Despite that breakthrough, hydrogen has not latched on as a dominant fuel source. Breaking down water into hydrogen can be inefficient and costly and the transformation process, called electrolysis, remains unperfected.UTEP Mechanical Engineering Professor Ramana Chintalapalle, Ph.D., who led the study said, “This is nature-inspired design in the laboratory. You have this plant with an extensive surface that can absorb moisture and survive in extreme environments. We thought, ‘How can we incorporate this into our research?’”

The Hydrogen Problem

Electrolysis is the process of splitting water with electricity and an electrocatalyst – a material that speeds up any chemical reaction. Current techniques to split water rely heavily on platinum as a catalyst, which has its drawbacks.

“Platinum is the dominant material used to help split water, but it is very expensive – more expensive than gold – and it’s just not feasible to use it on a large scale because of its price,” Chintalapalle explained. “We need a catalyst that’s more economically viable so every country can reasonably adopt hydrogen.”

A Prickly Solution

Navid Attarzadeh first noticed the prickly pear cactus while walking to UTEP’s Center for Advanced Materials Research lab. The team had been exploring nickel as a catalytic replacement for platinum, a metal that is abundant on Earth and 1,000 times cheaper than platinum.

Nickel, however, is not as quick and effective at breaking down water into hydrogen.

Attarzadeh said, “Every day, I passed this same plant. And I started connecting it to our catalyst problem. What caught my attention was how big the leaves and fruits were compared to other desert plants; the prickly pear has an extraordinary surface area.”

That’s when the Attarzadeh had an idea. What if they designed a 3D nickel-based catalyst in the shape of the prickly pear cactus? The larger surface area could accommodate more electrochemical reactions – creating more hydrogen than nickel typically can.

The team quickly designed the nano-scale structure – invisible to the human eye – and put it to the test.

“We tested the catalyst’s ability to split water repeatedly and had good results,” Chintalapalle said. He added that this is a fundamental discovery and the process needs further refinement, but it’s a step in the right direction.

“Hydrogen gas can transform energy technology for our country – without generating greenhouse gas emissions,” Chintalapalle said. “Our carbon footprint could be eliminated; we need to keep pursuing this.”

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Sounds great and probably is. But there remains the raw efficiency of the electricity needed to perform the electrolysis. There isn’t a huge gain – it closer to just a push. Then there is the storage matter. Hydrogen and di-hydrogen are the smallest atom and molecule and slip away through – practically anything.

Ask a metallurgist or just check. The effect of hydrogen on steels isn’t a good thing at all. Nature did a really good thing on earth locking hydrogen away in water. There is a lot of the Universe’s fuel right here.

We’re still a long way off from pumping some distilled water into the car for fuel and driving away. There is a lot yet to discover and learn.

Someday its going to get figured out.

By Brian Westenhaus via NewEnergyandfuel