采用溶胶-凝胶法和共沉淀法制备了一系列铜锌铝催化剂，并将其与ZSM-5分子筛联合使用，催化CO2加氢制低碳烯烃。对不同制备方法得到的铜锌铝催化剂进行N2物理吸附、X射线衍射(XRD)、氢气程序升温还原(H2-TPR)表征，研究了其在CO2加氢反应中的催化性能，比较了不同催化剂制备方法对催化剂CO2加氢制低碳烯烃反应性能的影响。反应结果表明：不同催化剂的制备方法能显著影响所制备催化剂的CuO颗粒尺度、比表面积以及Cu组分分散度，进而影响CO2加氢反应的性能。该体系中铜锌铝催化剂对CO2转化率及CO选择性影响较大，但对碳氢化合物中低碳烯烃的选择性影响不大。溶胶-凝胶法中采用柠檬酸络合制备的催化剂在反应温度320 ℃，CO2∶H2=1∶3，空速3 600 mL/（g·h）条件下，CO2转化率为20.17%，碳氢化合物中低碳烯烃选择性为50.48%。共沉淀法中碳酸钠沉淀剂制备催化剂在相同反应条件下，CO2转化率为29.14%，碳氢化合物中低碳烯烃选择性为54.57%。

A series of copper-zinc-aluminum catalysts were prepared by sol-gel method and co-precipitation method, which were used in combination with ZSM-5 molecular sieve to catalyze hydrogenation of CO2 to light olefins. The prepared catalysts were characterized by means of N2 physical adsorption, X-ray diffraction (XRD), and hydrogen temperature-programmed reduction (H2-TPR). The performance of the catalysts prepared by two different methods were comparatively investigated in CO2 hydrogenation to  produce light olefins. The results show that different catalyst preparation methods significantly affect the CuO particle size, specific surface area and Cu component dispersion of the prepared catalysts, which in turn affects the performance of CO2 hydrogenation reaction. In this system, the copper-zinc-aluminum catalyst has a great influence on CO2 conversion rate and CO selectivity, but has little effect on the selectivity of light olefins in hydrocarbons. The catalyst prepared by the sol-gel method with the aid of citric acid complexation affords 20.17% CO2 conversion with a total selectivity to light olefins of 50.48% at 320 ℃, CO2∶H2=1∶3, and space velocity of 3 600 mL/(g·h), whereas the catalyst prepared by the co-precipitation method with sodium carbonate gives 29.14% CO2 conversion with a total selectivity to light olefins of 54.57%. 

0 引言

1 催化剂制备与表征

   1.1 催化剂制备

   1.2 催化剂表征

   1.3 催化剂性能评价

2 结果与讨论

   2.1 XRD表征

   2.2 N2物理吸附

   2.3 H2-TPR表征

   2.4 催化剂性能评价

3 结论