Optimizing surfactant removal from a soft-templated ordered mesoporous carbon precursor: an in situ SAXS study

Max Valentin Rauscher; Malina Seyffertitz; Richard Kohns; Sebastian Stock; Heinz Amenitsch; Nicola Huesing; Oskar Paris

doi:10.1107/S1600576723003886

Optimizing surfactant removal from a soft-templated ordered mesoporous carbon precursor: an in situ SAXS study

J Appl Crystallogr. 2023 May 29;56(Pt 3):801-809. doi: 10.1107/S1600576723003886. eCollection 2023 Jun 1.

Authors

Max Valentin Rauscher¹, Malina Seyffertitz¹, Richard Kohns², Sebastian Stock¹, Heinz Amenitsch³, Nicola Huesing², Oskar Paris¹

Affiliations

¹ Chair of Physics, Department Physics, Mechanics and Electrical Engineering, Montanuniversität Leoben, Leoben, Austria.
² Department of Chemistry and Physics of Materials, Paris Lodron University Salzburg, Salzburg, Austria.
³ Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria.

Abstract

In situ small-angle X-ray scattering (SAXS) was employed to identify critical parameters during thermal treatment for template removal of an ordered mesoporous carbon precursor synthesized via a direct soft-templating route. The structural parameters obtained from the SAXS data as a function of time were the lattice parameter of the 2D hexagonal structure, the diameter of the cylindrical mesostructures and a power-law exponent characterizing the interface roughness. Moreover, detailed information on contrast changes and pore lattice order was obtained from analysis of the integrated SAXS intensity of the Bragg and diffuse scattering separately. Five characteristic regions during heat treatment were identified and discussed regarding the underlying dominant processes. The influence of temperature and O₂/N₂ ratio on the final structure was analyzed, and parameter ranges were identified for an optimized template removal without strongly affecting the matrix. The results indicate that the final structure and controllability of the process are optimum for temperatures between 260 and 300°C with a gas flow containing 2 mol% of O₂.

Keywords: calcination; in situ small-angle X-ray scattering; ordered mesoporous carbons; soft-templated carbons.

Grants and funding

We acknowledge CERIC-ERIC for financial support and allocation of beam time at TUG’s (Graz University of Technology) SAXS beamline at the ELETTRA Synchrotron Radiation Source via proposals 20212069 and 20217061.