A novel carbonized polydopamine (C‐PDA) adsorbent with high CO2 adsorption capacity and water vapor resistance

Novel carbonized polydopamine adsorbents (C‐PDAs) with high surface area, high CO2 adsorption capacity and superior moisture resistance performance were prepared by one‐step synthesis method using polydopamine as carbon precursor at different KOH/C ratios, and then characterized. CO2 and water vapor adsorption performances of C‐PDAs were examined separately by static adsorption and fixed‐bed experiments. Results showed that BET area and pore volume of C‐PDA‐4 were up to 3342 m2/g and 2.01 cm3/g, respectively. Its CO2 adsorption capacity reached up to 30.5 mmol/g at 25 bar, much higher than many other adsorbents including metal‐organic frameworks (MOFs). C‐PDAs prepared with high KOH/C ratios had low surface element concentrations of O and N resulting in low surface hydrophilic property. H2O(g) isotherm of C‐PDA was much lower than those on Mg‐MOF‐74, Cu‐BTC, and MIL‐101(Cr). Fixed‐bed experiments showed that co‐presence of water vapor in feed stream with 30% RH had negligible impact on CO2 working capacity of C‐PDA. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3730–3738, 2016