The XPS spectra of reduced samples are shown in Fig. 4D. For Co/
MnOx-H2O and Co/MnOx-BDO, the binding energy of the Co2p3/2 shows
peaks at 780.9 eV and 780.3 eV, and Co2p1/2 peaks are detected at
796.9 eV and 796.1 eV, respectively. The Co2p peaks of Co/MnOx-BDO catalyst
appear at lower position than that of Co/MnOx-H2O catalyst, indicating
higher electron density of surface cobalt atom. It is believed that the
higher electron density of surface cobalt atom on Co/MnOx-BDO catalyst
could significantly influence the reaction performance in FT synthesis.