N-doped grpahene aerogels are novel thermal insulation materials with three-dimension nano-porous structure from two-dimension sheets.These aerogels can show very low gaseous thermal conductivity (0.0116 W/(m·K)) at extremely low bulk density (0.0345 g/cm3).And their total thermal conductivity under atmospheric pressure (25 ℃) can be as low as 0.0230 W/(m·K), which is even lower than that of static air.With the further decreasing of the thermal conductivity of the sheets, these aerogels may become the next generation of thermal insulation materials with lower thermal conductivity and much lower density.However, the reaction process is still not so clear.To study the reaction process, this paper prepared N-doped graphene aerogels with graphene oxide (GO) suspension, paraphenylene diamine (PPD) and ammonia (NH3·H2O) by freeze-drying.And the aerogels with varied reaction time were characterized with X-ray photoelectron spectroscopy (XPS).The contents and speciation of various elements in the aerogels were obtained based on the spectra.With the prolongation of reaction time, the GO was gradually reduced and the PPD was doped in the reduced graphene oxide sheets.As a result, the content of C atoms gradually increases, yet that of O atoms decreasing.Meanwhile, since the volatilization of NH3·H2O, the content of N atoms also slightly decreases.From the XPS spectra, the peaks corresponding to "C-O" and "C-NH2" are reduced, and that corresponding to "C-NH" and "pyrrolic N" are increased.