Recipe for ‘entirely renewable energy’ from water is nearing reality

9th August, 2021.      //   General Interest  // 

energia-hidraulica-minihidraulica According to recent study, generating “totally renewable clean energy” from which water would be the sole waste product is possible — and scientists are “homing in” on the specific ways of doing so.

A Trinity College Dublin team is “fine-tuning” a method of splitting water molecules into their constituent atoms using renewable power to produce energy-rich hydrogen, which they believe may be stored and utilized in fuel cells.

The procedure is currently doable, and the electricity necessary to break the water molecules may be generated using wind or solar power. However, the notion has yet to take off in a major manner since the amount of energy necessary to create hydrogen from these renewable resources is still rather high.

Instead of capturing vast quantities of renewable energy, the new research shows that the same outcome may be obtained by utilizing a specific mix of other elements as catalysts to drive this process.

Although elements like ruthenium and iridium are known to be very efficient catalysts for splitting hydrogen and oxygen molecules in water, they are “prohibitively costly” and too rare to be utilized on a large basis.

Instead, the researchers used advanced quantum chemical modeling and strong computer tools to come up with metal combinations that might trigger the required reaction.

Quantum chemistry is the study of chemical systems using quantum mechanics, with an emphasis on electronic structures and molecular dynamics.

So far, the research has identified nine earth-abundant metal-ligand (glue) pairings as “highly intriguing prospects for experimental investigation.”

According to the study team, three metals stand out. It’s chromium, manganese, and iron, which are thought to be very viable prospects.

“Thousands of catalysts based around these key components can now be placed in a melting pot and assessed for their abilities as the hunt for the magic combination continues,” the team said.

“Two years ago, our work had made the hunt for the holy grail of catalysts seem a little more manageable. ,” said senior author Dr Max Garca-Melchor of Trinity College. “Now, we have taken another major leap forward by narrowing the search area significantly and speeding up the way we search,”

“Until recently we were looking for a tiny needle in a huge haystack. After reducing the size of the haystack, we have now hoovered up plenty of the remaining hay. To put a sense of scale on this, two years ago we had screened 17 catalysts. Now we have screened 444 and believe it won’t be long before we have a database with 80,000 ‘screenable’ catalysts in it.”

He stated: “How can we live sustainably? That is arguably the biggest and most pressing question facing 21st century society. I believe researchers from all disciplines can help to answer that, and we feel a particular strength of our pursuit is the multi-disciplinary approach we are taking.”

 

The journal article’s initial author is Trinity PhD candidate Michael Craig. He explained: “It seems hopeful that science could provide the world with entirely renewable energy, and this latest work provides a theoretical basis to optimise sustainable ways to store this energy and goes beyond that by pinpointing specific metals that offer the greatest promise.

“A lot of research has focused on the effective yet prohibitively expensive metals as possible candidates, even though these are far too rare to do the heavy lifting required to store enough hydrogen for society. We are focused on finding a long-term, viable option. And we hope we will.”

Scientists have cautioned that the energy demands for hydrogen production might outstrip the expansion of renewable resources, implying that hydrogen-hungry processes could drive up demand for fossil fuels in the short term if demand for hydrogen rises.

The findings were reported in Cell Reports Physical Science.