Italian research opens new possibilities for the hydrogen production and for the purification of polluted gases

The next issue of Science will report a study that explains the mechanism for oxygen release by cerium oxide. This material is an important catalyst that favors many fundamental reactions that have profound implications for energy storage and environmental issues. These reactions include, for example, the purification of polluted gases and the production of hydrogen as new energy vector for fuel cells. The present study could inspire the design of new efficient catalysts for producing a large variety of goods, e.g. plastic materials, fuels, fertilizers and drugs.

The mechanism of oxygen release was analyzed and described by studying the surfaces of cerium oxide (ceria). “Ceria-based materials are oxygen buffers, materials that allow to efficiently store or release oxygen, thus favoring a high catalytic activity and inducing a set of chemical reactions which would otherwise require higher pressures and temperatures” says Friedrich Esch (Laboratorio TASC INFM-CNR). “The production of more efficient catalysts is therefore of paramount importance for saving energy, increasing the safety of industrial processes, and reducing the environmental impact.”

Presently, most of the industrial processes employ heterogeneous catalysts, i.e. devices that are in a phase (solid), different from the one of the reactants (gases): “A typical example are exhaust catalysts capable of purifying the combustion gases” explains Stefano Fabris (National Simulation Center DEMOCRITOS INFM-CNR and SISSA). Most of the recent research has focused on the energy production from alternative sources, on the reduction of the environmental impact, and on the energy storage. To pursue these important objectives, new and more efficient catalysts are needed. “The design and production of these catalysts is clearly a priority issue and ceria-based materials are attracting a great deal of attention by the most advanced laboratories” says Paolo Fornasiero (Department of Chemistry at the University of Trieste, and INSTM).

The team includes researchers from different institutions (INFM-CNR, SISSA, and University of Trieste) all located in Trieste (Italy). The work combines two complementary, state-of-the art techniques: scanning tunneling microscopy that allows to obtain experimental images of the material surface with atomic resolution, and numerical modeling that describes theoretically their electronic and atomic structure by means of parallel computing.

The multidisciplinary character of Trieste as a research center and its high concentration of scientific institutions played a key role in this important scientific project. “Trieste has a tradition of excellence in the fields of numerical simulation and of experimental analysis of matter, as well as in the design and development of industrial catalysts” conclude Giovanni Comelli and Renzo Rosei of the Department of Physics at the University of Trieste, who coordinated the project.