resumo
D-glucosamine is investigated as a non-toxic and sustainable carbon/nitrogen (C/N) source for the templated synthesis of nitrogen-containing CMK-8 ordered mesoporous carbons (NOMCs) conceived for selective CO2 uptake. Pyrolysis temperature is varied during nanocasting using the KIT-6 silica hard template to tailor microporosity and nitrogen inclusions. NOMCs exhibit large surface area (600-1000 m2 g-1) and excellent pore ordering. The CO2/adsorbent interaction energy is estimated by the isosteric enthalpy of adsorption (-33-40 kJ mol-1) and Henry's constants. The role of nitrogen content (-7 -12 at.%) and of each type of N-species on CO2 adsorption is studied by X-ray photoelectron spectroscopy, and CO2/N2 selectivity is attributed, being pyridinic functionalities the most effective ones. NOMCs are tested at different temperatures, gas flow compositions, reversibility, and so on; in all tested conditions, they outperform a homologous bare sucrose-derived carbon. Enhancing micropore volume allows achieving maximum adsorption capacity in pure CO2 (1.47 mmol g-1 at 30 degrees C/0.9 bar), whereas increasing surface N-content accounts for the highest selectivity in CO2/N2 mixtures (20/80 v/v) at 35 degrees C/ 1 bar (maximum CO2 uptake 0.82 mmol g-1). The combination of a suitable C/N precursor and the hard templating synthetic route is effective for obtaining high-performing, sustainable, and reusable selective CO2 sorbents, without any activation steps or N-doping post-treatments.
palavras-chave
POROUS CARBON; ADSORPTION CAPACITY; RATIONAL DESIGN; PORE-SIZE; SEPARATION; CARBONIZATION; ADSORBENTS; PROGRESS; SILICAS; FACILE
categoria
Science & Technology - Other Topics; Materials Science
autores
Maruccia, E; Lourenco, MAO; Priamushko, T; Bartoli, M; Bocchini, S; Pirri, FC; Saracco, G; Kleitz, F; Gerbaldi, C
nossos autores
Mirtha A. O. Lourenço
Investigadoragradecimentos
The RECODE project received funding from the EU's H2020 (R&I) program under GA 768583. E.M., T.P., and F.K. acknowledge the funding support of the University of Vienna (Austria). The authors are thankful to Dr. Andreas Mautner for XPS measurement in the core facility and to Dr. R~emy Guillet-Nicolas for technical support.