Speeding Up Catalysts for Energy Storage

Researchers develop the fastest synthetic catalyst for producing hydrogen gas, potentially leading to a new environmentally friendly, affordable fuel.

catalysts
The longer the “arms” of the catalyst (that is, the greater the number of carbons in the alkyl chains), the faster the catalyst (blue). Image courtesy of the U.S. Department of Energy’s Environmental Molecular Sciences Laboratory

The Science

Energy from solar panels generally can’t be stored for rainy days because there is no efficient way to store the electricity. In contrast, photosynthetic bacteria store energy in chemical bonds. If energy from solar panels could be similarly stored in stable chemical bonds, such as those in hydrogen gas, it could be later used to power fuel cells or internal combustion engines. Researchers have now reported the fastest synthetic catalyst for hydrogen gas production to date, using a natural bacterial catalyst as inspiration.

The Impact

The findings could lead to the development of optimal strategies for producing environmentally friendly, affordable hydrogen fuel.

Summary

Nature uses catalysts to generate fuels to store energy in chemical bonds. Scientists have struggled to design fuel-producing catalysts based on cheap, earth-abundant metals that are as efficient and inexpensive as nature’s catalysts. A team from the Center for Molecular Electrocatalysis is addressing this challenge. The center is an Energy Frontier Research Center funded by the U.S. Department of Energy and led by Pacific Northwest National Laboratory. The researchers turned to a bacterial catalyst for inspiration, developing an inexpensive nickel-based catalyst that produces 45 million hydrogen molecules per second. Surprisingly, the key to speeding up the catalyst for energy storage was slowing it down! As they developed the bioinspired catalyst, the scientists tested their catalysts in reactions by combining the catalyst and acids in different media. They discovered that the synthetic catalyst produced hydrogen faster in a viscous liquid than in a free-flowing liquid, suggesting that by restricting catalyst movement, they might speed up the reaction. Moreover, lengthening the “arms” of the catalyst (that is, increasing the number of carbons in the alkyl chains) slowed their flopping movement and further sped up hydrogen gas production. The researchers conducted molecular modeling studies using a high-performance computer at the Environmental Molecular Sciences Laboratory (EMSL) to understand how the arms behave in different media. EMSL is a U.S. Department of Energy Office of Science user facility. The synthetic catalyst’s unique properties could pave the way for efficient and inexpensive hydrogen production to power fuel cells or internal combustion engines.

Source : U.S. Department of Energy