New platinum, palladium catalyst able to deal with methane emissions for good

Sample inside the analysis chamber of the X-ray photoelectron spectroscopy system at the Barcelona Research Center. (Image courtesy of Universitat Politècnica de Catalunya).

Researchers at the Universitat Politècnica de Catalunya, the University of Udine and the ALBA Synchrotron have discovered a palladium and platinum catalyst that is able to eliminate methane emissions from transport and other human activities to reduce global warming.

In a paper published in the journal Nature Communications, the scientists explain that methane concentrations in the atmosphere have more than doubled since pre-industrial times, mainly due to the increased use of natural gas in recent decades, although livestock and waste are also important sources of methane.

Even though LNG is considered a cleaner fuel compared to coal and its petroleum-based counterparts, the methane associated with its burning has 34 times the warming power of CO2 over 100 years and 86 times over 20 years.

According to the researchers, curbing methane emissions can limit global warming in the short term, buying humanity some time to end CO2-induced warming for good.

In their view, one of the most effective ways to remove methane is to use a catalyst that accelerates its oxidation by air.

In the paper, they explain that for some time, the best catalysts for removing methane used palladium nanoparticles supported by ceramic oxides. However, these catalysts stop working in the presence of water vapour, which is always the case in natural gas combustion. To solve this issue, the researchers propose adding platinum atoms to the palladium nanoparticles.

To get to this solution, the scientific team matched the data obtained in experiments carried out at three different beamlines of the ALBA Synchrotron and studied the active sites of the catalyst while in operation: X-ray photoelectron spectroscopy, X-ray diffraction and X-ray absorption. Using synchrotron light, they discovered that palladium and platinum oxidation states play a key role in methane removal and that catalysts prepared using mechanochemical methods are more active and perfectly water-resistant.

“This type of catalyst has proven to be the most effective when it comes to eliminating methane,” the group said in a media statement.

The researchers believe that the new substance can, thus, be applied to catalytic converters on combustion engine vehicles and to natural gas domestic boilers and turbines.