Ni-Mo-Nd-ZrO_x催化剂在乙醇水蒸气重整制氢反应中的性能

Performances of Ni-Mo-Nd-ZrO_x catalysts in steam reforming of ethanol for hydrogen production

以草酸铵为沉淀剂,采用共沉淀法制备Nd-Zr O_x载体,用浸渍法负载活性组分Ni-Mo,制备出Ni-Mo-Nd-Zr O_x系列催化剂,考察了催化剂在乙醇水蒸气重整制氢反应中的催化活性。采用XRD和TPR表征方法对催化剂的晶体结构及还原特性等进行表征。表征结果显示,载体主要成分为(Zr_(0.9)Nd_(0.1))O1.95固溶体,存在少量立方相Nd_2O_3;负载的Ni组分以四方相Ni O形式高度分散于载体表面,并生成少量尖晶石结构Ni Nd_2O_4;催化剂经过600℃的H_2还原后,只有四方相Ni O被还原为立方相Ni单质。实验结果表明,催化剂在乙醇水蒸气重整制氢反应中表现出良好的催化性能,在600℃下,(Ni_(9.69)Mo_(0.323))/Ni-Mo-Nd-ZrO_x催化剂上乙醇转化率达到100%,H_2选择性为69.14%,未发现催化剂失活、积碳和烧结等现象,稳定性良好。

Nd-Zr O_x support was synthesized through coprecipitation and then Ni-Mo-Nd-Zr O_xcatalysts were prepared through impregnation. The activities of the catalysts in ethanol steam reforming were studied in a fixed bed reactor. The catalysts were characterized by means of XRD and TPR to investigate their crystalline phases and reducibility. The results showed that the major components of the support was solid solution（Zr_（0.9）Nd_（0.1））O_（1.95） and there was a small amount of cubic phase Nd_2O_3;Ni component was highly dispersed on the support surface in the form of cubic Ni O and a little of Ni Nd_2O_4 spinel formed. Cubic Ni was found on the catalysts after reduction with hydrogen at 600 ℃. The catalysts showed high catalytic activities in the ethanol steam reforming. Under the conditions of（Ni_（9.69）Mo_（0.323））/（Nd_8Zr_（32））O_x as the catalyst and reaction temperature 600 ℃,the conversion of ethanol and the selectivity to H_2 were nearly 100% and 69.14% respectively,and carbon deposition,sintering and catalyst deactivation were not found in the reaction process.