Spatial tuning of adsorption enthalpies by exploiting spectator group effects in organosilica carbon capture materials

verfasst von
Mario Evers, Karin Hauser, Wolfgang G. Hinze, Nele Klinkenberg, Yasar Krysiak, Daniel Mombers, Sebastian Polarz
Abstract

Functional gradient materials can process more complex tasks than a mixture of their homogeneous analogs. Generating such materials is difficult as it necessitates spatial control over chemical and/or structural properties. A gradient is a unique degree of freedom in hierarchical material architectures, and as such, biology has managed exploiting the full potential of graded structures. For instance, despite being present at a comparably low concentration (approaching 420 ppm in 2023), plants are capable of capturing carbon dioxide from the air. Binding occurs in the carboxysome, a complex entity characterized by pores with engineered surfaces composed of shell proteins that create a concentration gradient of CO2 towards an enzyme responsible for the first conversion step. The current paper hypothesizes that porous organosilica materials can mimic some of the features of the mentioned biological paragon. Primary amines as sites for interacting with CO2 are surrounded by spectator groups on bifunctional surfaces. It is found that the proper choice of the spectator group almost doubles the adsorption enthalpy. Above a critical density, the hydrophobic moieties create a quasi-solvent layer on the surfaces in which CO2 molecules dissolve. When the density of the spectator groups gradually changes inside a graded organosilica monolith, one obtains zones varying systematically in adsorption enthalpy. Directionality in affinity towards CO2 and controlled transport properties are realized.

Organisationseinheit(en)
Institut für Anorganische Chemie
Externe Organisation(en)
Universität Konstanz
Typ
Artikel
Journal
Journal of Materials Chemistry A
Band
12
Seiten
11332-11343
Anzahl der Seiten
12
ISSN
2050-7488
Publikationsdatum
21.05.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Allgemeine Chemie, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Allgemeine Materialwissenschaften
Ziele für nachhaltige Entwicklung
SDG 7 – Erschwingliche und saubere Energie
Elektronische Version(en)
https://doi.org/10.1039/d4ta01381f (Zugang: Offen)