Palladium Catalyst 'May Hold Key' to Efficiency
Source: Platinum Today (12/2/10)
"The palladium complex 'solves half the problem' of methane-to-ethane conversion."
The main problems associated with reversing combustion until now are that making carbon dioxide into a fuel uses too much energy and produces more of the gas than it reclaims.
However, Liviu M Mirica, Assistant Professor of Chemistry in Arts and Sciences at Washington University in St Louis, believes metal catalysts could provide the solution.
Last year, he successfully catalysed the splitting of water with a palladium compound, noting that its easy oxidisation hints at greater potential for making hydrocarbon combustion reactions run backwards.
"So then we asked, what else could we use it for? One of our ideas was to use it to turn methane into ethane," said Professor Mirica.
According to the university, the palladium complex "solves half the problem" of methane-to-ethane conversion by combining two methyl groups in the presence of oxygen and light.
In the system, an organic molecule binds a central palladium atom through four nitrogen atoms, holding it firm, and stabilises the complex in the unusual '+3' oxidation state.
This accounts for its ability to be reversible, with the palladium atom offering two docking spots which can be taken by substances which it may be able to catalyse.
Professor Mirica filled these openings with the methyl groups, which then produced ethane, and the expert believes the process could be used for building longer-chain hydrocarbons such as butane and octane.
"Carbon dioxide is an exceptionally stable molecule, so anything you do with it is going to require energy," he concluded.
"We're just trying to use the metal complex to minimise the energy input."