Carbon Dioxide Reforming Of Methane Catalytic Materials And Research

Catalytic reforming of methane with carbon dioxide caneffectively utilize two types of greenhouse gases, CO2and CH4. Thesyngas produced has a low ratio of H2/CO (less than1), which can beused as feedstock for Fischer-Tropsch synthesis. Moreover, CH4/CO2reforming reaction is strong endothermic reaction，which can be usedfor energy storage. Therefore, this subject has been widely researched.Nowadays, Ni-based catalysts were widely investigated, due to theirmuch lower price than noble metal catalysts. However, carbondeposition and easily inactivation are the mainly problems of Ni-basedcatalysts.In this graduation thesis, Ni/silicalite-1and Ni/KIT-6catalysts weresynthesized with the different Ni content, which use microporousmolecular sieve silicalite-1and mesoporous molecular sieve KIT-6assupports, respectively. The effects of reaction temperature, reactiontime, Ni content and gas hourly space velocity were investigated. XRD,TEM, TG/DGA techniques were used to characterize the catalysts. Theresults indicated that all the catalysts presented carbon deposition.When the Ni content was6%, the initial catalytic activity of thesecatalysts was the best. After5h reaction, Ni/KIT-6catalysts were morestable than Ni/silicalite-1, due to good coke-resistant.Then, novel Ni-KIT-6catalysts were synthesized by a one-spotco-assembly method. The effects of reaction temperature, reactiontime, Ni content were investigated. The result showed that theconversions of CH4and CO2were90%and94%at800℃, respectively,and the lifetime of the catalyst could reach170h. In addition, XRD, BET,XPS, FT-IR etc. techniques were used to characterize Ni-KIT-6catalysts.Compared with the characterization results of6%Ni/KIT-6, Ni-KIT-6catalysts have bigger pore diameter,(to16nm), besides, the Ni particle of Ni-KIT-6had stronger interaction with the support, and large amountsof Ni particle were incorporated into the pore walls. In addition, it isindicated nickel particle presented wonderful dispersive distribution inthe pore walls, with particle size less than5nm. Furthermore, it wasfound that after a period of time reaction, there was no significantcarbon deposition over the spent Ni-KIT-6catalysts, which indicatedthat it had good anti-coke performance.