CuO-ZnO/(SAPO-34)-高岭土催化CO2加氢合成低碳烯烃

Hydrogenation of CO2 to Light Olefins on CuO-ZnO/(SAPO-34)-kaolin

摘要:

以廉价的高岭土为原料，三乙胺为模板剂，采用水热法制备了负载型甲醇脱水催化剂(SAPO-34)-高岭土，用XRD、SEM、EDS、BET、H2-TPR及NH3-TPD对合成的催化剂进行了表征。结果表明，以高岭土为硅源和铝源制备的SAPO-34分子筛以剩余的高岭土为载体原位生长于高岭土表面，有效地提高了SAPO-34分子筛的分散性，且具有较高的结晶度。通过将CuO-ZnO负载于(SAPO-34)-高岭土表面制备了双功能催化剂CuO-ZnO/(SAPO-34)-高岭土，将其用于催化CO2加氢制备低碳烯烃，在反应温度为673 K、反应压力为3 MPa、空速为1800 mL/(gcath)、V(CO2) : V(H2) = 1:3的条件下，CO2单程转化率为43.5%，低碳烯烃的选择性和产率分别为63.8%和27.8%。在连续8 h的催化性能测试中，低碳烯烃的产率维持在18.7%，表现出较长的催化寿命。

Abstract:

Load-type methanol dehydration catalyst of (SAPO-34)-kaolin was prepared by hydrothermal method using kaolin as a low-cost material and triethylamine as template agent. The synthesized catalysts were characterized by XRD, SEM, EDS, BET, H2-TPR and NH3-TPD techniques. The results show the synthesized SAPO-34 molecular sieves prepared by Si and Al of kaolin grow in situ at the surface of residual kaolin. (SAPO-34)-kaolin has good dispersity and relatively high crystallinity. CuO-ZnO/(SAPO-34)-kaolin was prepared through loaded CuO-ZnO to the surface of (SAPO-34)-kaolin, which can be used for synthesis of light olefins from CO2 hydrogenation. Under the condition of temperature at 673 K, pressure at 3 MPa, airspeed at 1800 mL/(gcath) and V(CO2) / V(H2) = 1:3, the one-way conversion of CO2 could reach up to 43.5%, with a light olefins selectivity and yield of 63.8% and 27.8%, respectively. For a continuous performance as long as 8 h, the yield of light olefins is over 18.7%.