Abstract：The technology of H2S reforming with CH4 for hydrogen production provides a new technical route to comprehensive utilization of both sour natural gases having high H2S contents and the large amount of H2S exhausted from refinery hydrodesulfurization plants. Mo/Al2O3 catalyst is an active one for the reaction between H2S and CH4 to produce H2, however, behaving a drawback of poor stability accompanying with itself. In order to modify the catalyst stability, in this paper, a series of Mo/Al2O3 catalysts with different Co addition amount (mass fraction 1%-20%) were prepared using co-impregnation method and a commercial ?-Al2O3 (denoted as Al2O3) as the support. The catalytic performances of these catalysts were tested and compared in term of both H2S and CH4 reaction rates and H2 generation rate varying with reaction time on stream under the conditions of 0.1 MPa, 800 ℃, volume ratio of H2S to CH4 1:5, and gas hourly space velocity of 20 000 h-1. The results showed that the addition of Co failed to effectively slow the performance decline of the 20%Mo/Al2O3 catalyst and it could improve the CH4 conversion activity. With the increase of Co amount, the CH4 reaction rate was improved, and the H2 generation rate was raised as a result of increased CH4 decomposition rate. Nevertheless, the presence of Co was not beneficial to H2S conversion, and the carbon deposition amount on the catalyst also increased. The multiple characterization of catalyst structures and properties reveals that the acceleration of CH4 decomposition was associated with Co3Mo alloy formation after Co adding to 20%Mo/Al2O3 catalyst, leading to substantial carbon deposition with graphene layer or carbon nanotube structure. The cover of carbon deposition on the active edge sites of MoS2 particles and the growth of MoS2 particles at high reaction temperature are the main causes of catalyst deactivation.
WU Jingxian,MA Zhejie,REN Haitao et al. Influence of Co Addition on the Stability of Mo/Al2O3 Catalysts During Hydrogen Sulfide Reforming with Methane for Hydrogen Production[J]. Chemical Reaction Engineering and Technology, 2021, 37(6): 489-495.
