Activated carbon materials with a rich surface chemistry prepared from L-cysteine amino acid

A series of activated carbon materials have been successfully prepared from a non-essential amino acid, such as L-cysteine. The synthesized carbons combine a widely developed porous structure (BET surface area up to 1000 m(2)/g) and a rich surface chemistry (mainly oxygen, nitrogen and sulphur functionalities). These surface functional groups are relatively stable even after a high temperature thermal treatment (O>N similar to S). Experimental results show that these samples with a rich surface chemistry exhibit a significant improvement in their hydrophilic character. Although the role of the surface functional groups is less pronounced for the adsorption of non-polar molecules such as CO2, CH4 and C2H4, their adsorption at atmospheric pressure is to some extend conditioned by the characteristics of the adsorbent-adsorbate interactions. The synthesized carbons exhibit an excellent adsorption performance for CO2 (up to 3 mmol/g at 0 degrees C). Furthermore, samples with a low activation degree exhibit molecular sieving properties with very promising CO2/CH4 (up to 4.5) and C2H4/CH4 (up to 6) selectivity ratios. These results anticipate that non-essential amino acids are a versatile platform to obtain carbon materials combining a tailored porous structure and rich multifunctional surface chemistry and with potential application for gas adsorption/separation processes. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

Activated carbon materials synthesized from non-essential amino acids exhibit a tailored porous structure and rich multifunctional surface chemistry, resulting in improved hydrophilic character and excellent CO2 adsorption performance. Samples with low activation degree show molecular sieving properties with high selectivity ratios.