Air pollution from fuel combustion is a great environmental problem. The presence of nitrogen oxides and carbon monoxide (CO) in the air of densely populated cities seriously harms the human health and increases mortality. Collaboration between researchers from the Universitat de Barcelona (UB) and the Boreskov Institute of Catalysis (BIC) of the Russian Academy of Sciences in Novosibirsk opens a way for reducing polluting car emissions. In a study published in the Applied Catalysis B: Environmental journal the scientists propose design principles and synthesize catalysts for transforming toxic molecules in air at temperatures even below 0ºC.
Most of toxic molecules generated in combustion engines are abated by transforming them into harmless molecules in the catalytic converters. The majority of the harmful pollutions during an average drive are cold-start emissions generated by cars during the first few minutes after ignition, when the motors are insufficiently warm for the catalyst to start operating. Thus, the design of catalysts working at low temperatures remains a challenge.
To address this challenge, the BIC researchers explored low-temperature efficiency of catalysts and identified particular formulations able to convert CO already at -50°C. This extraordinary lowtemperature efficiency was achieved by dispersing metal platinum (Pt) on nanostructured cerium oxide (CeO2). The key to this performance is the synergy between the oxide and distributed thereon oxidized platinum. These components can be identified spectroscopically, but characterizing their roles requires computational modelling. The UB team of ICREA Professor Konstantin Neyman modelled these materials using sophisticated quantum mechanical computer calculations to decipher the role of each component in the outstanding catalytic performance measured experimentally.
The societal impact of this advancement in the developing of catalytic materials for the lowtemperature oxidation of air pollutants is not limited to automotive emissions. These materials can also be used for the oxidative abatement of the pollutants produced by stationary sources, such as fossil-fuelled power plants.
