Cutting-edge modelling methods from USI help unlock the secrets of porous material

Most materials have a seemingly smooth surface, but under high magnification, they reveal to be full of tiny holes or pores. Zeolites, in particular, have pores in different sizes that allow them to be used in a range of different applications like catalysis, the branch of chemistry that studies how to accelerate chemical reactions, a fundamental pillar for the chemical industry. However, many fundamental questions remain about what actually happens inside the pores of a zeolite and, more precisely, how water influences the overall behaviour of the system. A team of research labs, including the Euler Institute at USI, have found answers to these questions, suggesting new ways to create designer zeolites.

To the naked eye, most materials have a relatively smooth surface. But under high magnification, those surfaces can be full of tiny holes or pores. Porous materials serve a range of useful purposes, from separating chemicals to converting organic molecules into desired products or fuels. One such class of materials, zeolites, are known to have pores in different sizes that allow them to be used in a range of different applications like catalysis, the branch of chemistry that studies how to accelerate chemical reactions, a fundamental pillar for the chemical industry. However, many fundamental questions remain about what actually happens inside the pores of a zeolite and, in particular, how water influences the overall behaviour of the system. Since water is present in many key chemical transformations, not understanding its role limits the efficacy of strategies aimed at controlling zeolite reactivity.

A group of scientists at the USI Euler Institute, Pacific Northwest National Laboratory (USA), and the Istituto Italiano di Tecnologia in Genoa, used computer simulations to explain how water inside zeolite pores affects how well they perform useful chemical reactions. Their results help explain previous confounding experimental observations and suggest new approaches to creating designer zeolites.

"Catalysis is the beating hearth of chemistry but many of its fundamental aspects remain unclear. These simulations shed light on a fundamental problem which has important consequences in terms of energy conversion technology and sustainable chemistry. Our ultimate goals is to understand better the materials properties to improve its performances", explains Euler Institute researcher GiovanniMaria Piccini, who worked on this project at USI, coordinating the PhD dissertation of Emanuele Grifoni and together with professor Michele Parrinello.

The findings, detailed in Nature Communications, explored the much-debated role of water in zeolites, showing that water forms clusters on the walls of the pores, like moss on a rock, regardless of pore size or other zeolite properties. The research team used statistical methods for modelling complex chemistry developed by the team members in Italy and Switzerland to tackle the challenge. This study also shows the successful application of a cutting-edge computational method to a catalytic system and the identification of the role of water clusters in controlling zeolite acidity.

"The methods that we develop at the Euler Institute allow us to study these problems from a different angle and we are excited to use them to investigate real problems of industrial and environmental relevance", adds Piccini.

Read the full news release at: 
www.newswise.com/doescience/water-clusters-control-zeolite-reactivity/?article_id=751104

The original scientific article Confinement effects and acid strength in zeolites is currently among the "Editor's features" on Nature  Communications: 
www.nature.com/collections/wtpqpqpgwd