低镍/ZnO-TiO_2催化剂的乙醇水蒸气重整制氢

Hydrogen Production from Ethanol Steam Reforming over Low Nickel Content Ni/ZnO-TiO_2 Catalysts

为考察低镍负载量对乙醇水蒸气重整制氢催化剂性能的影响,利用沉积-沉淀法(DP)制备了镍负载量质量分率为0.5%～5.0%的Ni/ZnO-TiO_2催化剂,并在内径14mm的固定床管式反应器中对低镍催化剂进行了性能评价。结果表明,低镍/ZnO-TiO_2催化剂具有较好的乙醇水蒸气重整制氢性能,在水醇物质的量比为13:1及反应温度为400～550℃时,乙醇转化率均达到了90%以上,其中镍负载量为2%的催化剂有最好的催化性能。对镍负载量2%的2.0Ni/ZnO-TiO_2催化剂进行了X射线衍射(XRD)和扫描电镜(SEM)表征,分析结果表明,复合载体ZnO-TiO_2负载的Ni基催化剂的晶体粒径为68～240nm,活性组分Ni分散良好,反应后的催化剂上有积炭生成。

In order to explore the influence of low nickel loading on the characteristics of hydrogen production from ethanol steam reforming, Ni/ZnO-TiO2 catalysts in the nickel loading range 0.5%-5.0% were prepared by deposition-precipitation （ DP ） method, and the catalytic performances were evaluated in a Ф14 mm fixed bed tube reactor. The results showed that Ni/ZnO-Ti02 catalysts have better catalytic performance for hydrogen production of ethanol steam reforming. Ethanol conversion was beyond 90% under the conditions of the molar ratio of water to ethanol of 13：1 and the reaction temperature of 400-550 ℃. The catalyst with 2% nickel loading showed the best catalytic performance comparatively. Catalyst with the nickel loading of 2% was by means of BET, x-ray diffraction （XRD） and scanning electron microscope （SEM）. The results characterized by XRD and SEM indicated that the crystal sizes of Ni-based catalyst supported on composite support of ZnO-TiO2 were 68-240 nm, the active component nickel was dispersion well, and formation of carbon could found on used catalyst surface.