Adsorption properties of nitrogen-alloyed activated carbon fiber Original Research Article

N-alloyed activated carbon fibers (ACFs) were prepared by chemical vapor deposition (CVD) of pyridine on pitch-based ACF at 1023 K and 1273 K for 1 h. The N-alloyed ACFs were characterized by using the N2 adsorption at 77 K, CO2 adsorption at 273 K, elemental analysis, and X-ray photoelectron spectroscopy (XPS). The nitrogen content increases as a result of the pyridine-CVD. XPS examination showed that the percent of quaternary nitrogens in nitrogen structures increases remarkably from 60 to 91% for CVD temperatures of 1023 and 1273 K, respectively. The effects of N-alloying on adsorption properties of ACFs for C2H5OH and H2O were examined at 303 K. Both N-alloyed ACFs have a larger fractional filling of C2H5OH molecules. The uptake pressure of the H2O adsorption branches of both N-alloyed ACFs shifts to a lower relative pressure, compared with that of pristine ACF. Furthermore, the ratios of the VH2O (saturated amount of H2O at P/P0=1) to W0N2 (pore volume determined by N2 adsorption at 77 K) of N-alloyed ACFs are much larger than that of pristine ACF.