Stanford University scientists are improving liquid fuel storage techniques by developing new catalytic systems for isopropanol production to optimize energy retention and release.
As California rapidly transitions to renewable fuels, it needs new technologies that can store electricity for its electric grid. Solar energy decreases at night and decreases in winter. Tidal wind energy. As a result, the state relies heavily on natural gas to offset the ups and downs of renewable energy.
“The grid consumes energy at the rate you produce it, and if you’re not currently using it and storing it, you have to throw it away,” said Robert Weymouth, the Robert Eccles Swain Professor of Chemistry. at the School of Humanities and Sciences
Waymouth is leading a team at Stanford University to work on liquid organic hydrogen carriers (LOHC), a new renewable energy storage technology. Hydrogen is already used as fuel or a means of generating electricity, but it is difficult to store and transport.
“We are developing a new strategy for the selective conversion and long-term storage of electrical energy in liquid fuels,” said Weymouth, the study’s senior author, who detailed the work in the Journal. American Chemical Society . “We also discovered a new selective catalytic system for storing electrical energy in liquid fuels without producing hydrogen gas.”
liquid batteries
In addition to batteries used to store electricity in the network, smartphone and electric car batteries also use lithium-ion technology. Because of the scale of energy storage, researchers continue to search for systems that can complement these technologies.
Candidates include LOHCs that can store and release hydrogen using catalysts and high temperatures. LOHCs may one day function as “liquid batteries” in general, storing energy and efficiently recycling it as usable fuel or electricity when needed.
The Waymouth team is examining isopropanol and acetone as ingredients in hydrogen energy storage and release systems. Isopropanol – or medical alcohol – is a high-density form of liquid hydrogen that can be stored or transported through existing infrastructure until it is time to use it as fuel in fuel cells or release the hydrogen for carbon-free use.
However, methods of obtaining isopropanol with the help of electricity are ineffective. Two protons and two electrons from water can be converted into hydrogen gas, then the catalyst can produce isopropanol from this hydrogen. “But you don’t need hydrogen in this process,” Weymouth said. “The energy density per unit volume is low. We need a way to produce isopropanol directly from protons and electrons without producing hydrogen gas.”
The study’s lead author, Daniel Marron, who recently earned his doctorate in chemistry from Stanford University, determined how to solve this problem. He developed a catalytic system that combines two protons and two electrons with acetone to selectively produce LOHC isopropanol without the production of hydrogen gas. He did this by using iridium as a catalyst.
The real surprise was that cobaltocene was the magic additive. Cobaltocene, a chemical compound of the inexpensive metal cobalt, has long been used as a simple reducing agent and is relatively inexpensive. The researchers found that cobaltocene was extremely efficient when used as a cocatalyst in this reaction, delivering protons and electrons directly to the iridium catalyst rather than releasing hydrogen gas as previously expected.
basic future
Cobalt is already a widely used material for batteries and is in high demand; So the Stanford team hopes their new understanding of the properties of cobaltocene will help scientists develop other catalysts for the process. For example, researchers are investigating more common base metal catalysts, such as iron, to make future LOHC systems more affordable and scalable.
“This is basic basic science, but we think we have a new strategy for more selective storage of electricity in liquid fuels,” Weymouth said.
As this work progresses, it is hoped that LOHC systems could improve energy storage for the industrial and energy sectors or for individual solar or wind farms.
Waymouth concluded that despite all the complex and complex work behind the scenes, the process is actually quite elegant: “When you have excess energy and there is no demand for it on the grid, you store it as isopropanol. “When you need energy, you can get it back as electricity.”
Source: Port Altele
