Abstract:

The effects of passivation and sulfidation on the bulk structure and surface properties of Mo2N were studied by using XRD, H2-TPD and TPS methods. The characterization results of Mo2N combined with the pyridin HDN activity show that the surface properties of Mo2N are changed significantly after passivation or sillfidatior in spite of the bulk structure unchanged. The H2-TPD profile for passivated Mo2N is obviously different from that of the fresh one and the pyridin HDN activity 0ver passivated Mo2N is much lower as well. According to the behavior of Mo2N in different passivating conditions and H2-TPD results, we suggest that the passivation 0f Mo2N produces Mo2 on the sample surface. Based on the H2-TPD profiles and the pyridin HDN activity over Mo2N samples which either had been sulfidized or not and the TPS profiles, we conclude that the surface structure of molybdenum nitride has been changed to sulfide under sulfiding condition.

Key words: Passivation, Mo₂N, Sulfidation, HDN