Radoslav Adzic (Credit: BNL)

Hydrogen fuel cells, which generate electricity in the process of converting hydrogen and oxygen into water, have long been known as difficult to produce, due to issues related to hydrogen production, storage, and transport. These complications led researchers to consider using hydrogen-rich compounds, specifically liquid ethanol, in what is today known as the "Direct Ethanol Fuel Cell." "Ethanol is one of the most ideal reactants for fuel cells," says Radoslav Adzic, senior chemist at BNL. "It's easy to produce, renewable, nontoxic, relatively easy to transport, and it has a high energy density. In addition, with some alterations, we could reuse the infrastructure that's currently in place to store and distribute gasoline."

Yet despite the above advantages, ethanol does have a major setback - its molecules achieve very slow and insufficient oxidation, a process responsible for breaking the compound into hydrogen ions and electrons. This has previously been the bottleneck point for efficient production of ethanol fuel cells, as scientists were unsuccessful in finding a proper catalyst that will be able to break the bonds between ethanol's carbon atoms.

Model of a ternary electrocatalyst for ethanol oxidation consisting of platinum-rhodium clusters on a surface of tin dioxide. This catalyst can split the carbon-carbon bond and oxidize ethanol to carbon dioxide within fuel cells (Credit: BNL)

The new electrocatalyst, which is made of platinum and rhodium atoms on carbon-supported tin dioxide nanoparticles, was proven capable of breaking carbon bonds at room temperature and efficiently oxidizing ethanol into carbon dioxide - this as opposed to common catalysts, which produce acetalhyde and acetic acid as their main reaction products and are thus unsuitable for power generation purposes. "The ability to split the carbon-carbon bond and generate CO2 at room temperature is a completely new feature of catalysis," Adzic said. "There are no other catalysts that can achieve this at practical potentials."

 

Brookhaven researchers say their ternary catalyst's structural and electronic properties, which were determined using x-ray absorption techniques combined with data from transmission electron microscopy analyses at the Center for Functional Nanomaterials at BNL, show it to be applicable to a variety of other alternative energy solutions. "These findings can open new possibilities of research not only for electrocatalysts and fuel cells but also for many other catalytic processes," Adzic said.

 

The developed catalyst is currently undergoing extensive testing, as scientists are assessing its performance in a real fuel cell.

TFOT has previously covered a number of innovative technologies for power generation, including sugar-powered batteries, which were developed by Sony; the world's smallest fuel cell, invented at University of Illinois at Urbane-Champaign, and a new bio-fuel powered sports car developed by the Swedish car manufacturer Koenigsegg.

More information on the new catalyst can be found here.