【作者】 梁义；

【导师】 石秋杰；

【作者基本信息】 南昌大学 ， 物理化学， 2007， 硕士

【摘要】 本文是从目前主要的乙醇制氢的方法入手，论述了水蒸气重整、部分氧化重整、等离子体重整、光催化诱导重整、膜分离等不同的乙醇的重整制氢方式。并选择以Ni／ZnO催化乙醇水蒸气重整的制氢为研究体系。考察了通过对催化剂Ni／ZnO进行Mo改性以及ZrO2的添加对整个乙醇水蒸气重整制氢体系的影响。实验结果表明，在Mo改性的Ni／ZnO乙醇水蒸气重整制氢体系中。采用了X-射线衍射（XRD）分析催化剂的结构及粒径的大小；程序升温还原（TPR）法研究了催化剂的还原性能；程序升温氧化（TPO）法分析了催化剂抗积碳的能力。温度为773K时适量Mo的添加能提高Ni／ZnO催化剂的活性和氢气选择性；Ni／ZnO及Ni-Mo／ZnO催化剂的活性随着温度的升高而提高，823K时乙醇完全转化；在反应温度为873K时，Mo的含量为0.83％的Ni-Mo／ZnO催化剂对氢气的选择性最高；Mo的添加可以提高Ni／ZnO催化剂的抗积碳能力从而提高该催化剂的稳定性。TPR和XRD实验结果说明了Mo的添加有利于Ni氧化物在载体上的分散；减弱氧化态镍物种与载体之间的作用，从而提高了催化剂的活性、选择性和稳定性。在以ZnO-ZrO₂为载体的镍基乙醇水蒸气重整制氢中，以草酸钠为共沉淀剂，采用了共沉淀法制备了催化剂（Ni／ZnO-ZrO₂）。考察了比例不同的ZnO-ZrO₂负载的镍基催化剂在300～650℃下催化乙醇水蒸气重整制氢反应的性能。用TPR、TPO、XRD对催化剂试样进行了表征。结果表明，400℃下，在所有的催化剂上乙醇均已完全转化；在低温时，ZnO-ZrO₂的复合载体上，氢气的选择性要比单一载体的选择性高；含ZrO₂的催化剂的积碳量都比较小，这是因为立方晶系的ZrO₂可以提高ZnO-ZrO₂晶格氧的表面富集能力，降低催化剂上积炭量。本文还比较了氢气预还原对催化剂活性和抗积碳能力的影响。结果表明，未还原的催化剂对氢气的选择性要比已还原的催化剂的高。未还原的催化剂NZr、NZZ抗积碳能力比已还原的催化剂高，而催化剂NZn则相反。其原因可能是未还原的催化剂活性物种比还原后的催化剂的活性物种分散好，粒子小，也可能因为还原前后的表面活性物种发生了改变，从而影响了活性及抗积碳能力。更多还原

【Abstract】 The different ways of reforming ethanol to generate hydrogen were reviewed inthe thesis, such as steam reforming, partial oxidation reforming, plasma reforming,photocatalysis induced reforming and separate membrane reaction. Effect of Mo andZrO₂ t on the properties of Ni/ZnO for ethanol reforming to generate hydrogen wasstudied.The structure and size of the catalysts were analyzed by means of X-raydiffraction（XRD）. The reductive property of the catalysts was characterized bytemperature programmed reduction（TPR） and the ability of resistance to carbondeposition of the catalysts was tested by temperature programmed oxidization.The results showed that the activity and selectivity to H₂ of Ni/ZnO catalyst arepromoted by addition of Mo at 773K. The activities of the catalysts increase with thetemperature. Ethanol is converted completely at 823K. At 873K, NMZ-2 catalyst, inwhich the content of Mo was 0.83%, has the optimum activity, the highest selectivitytowards hydrogen and the best stability among the catalysts. The ability ofresistance to carbon deposition of NZ can be promoted by addition of Mo,therefore,the stability of the catalyst is improved. TPR and XRD results show that addition ofMo increases the dispersion of nickel oxide over ZnO and weakens the interactionbetween Ni oxide and the support. Therefore, the activity, selectivity and stability ofNi/ZnO catalyst are improved.The Catalyst Ni/ZnO-ZrO₂ used in ethanol steam reforming were prepared by acoprecipitation method using Na₂C₂O₄ as a precipitant. The catalytic properties of thecatalysts with different ratio of ZnO:ZrO₂ between 300 and 650℃were discussed.The catalysts were characterized by means of TPR, TPO and XRD. The resultssuggested that ethanol was conversed compeletely at 400℃. The selectivites tohydrogen over Ni/ ZnO-ZrO₂ were higher than Ni/ ZnO and Ni/ ZrO₂ at lowtemperature. Meanwhile. the amount of carbon deposition on Ni/ZnO-ZrO₂ and Ni/ZrO₂ was less than that on Ni/ ZnO. the cubic ZrO₂ could enhance the surface accumulating ability of lattice oxygen in ZnO-ZrO2, decreasing the amount of carbondeposited.The thesis also studed the effect of hydrogen reduction on the catalytic propertiesof Ni/ZnO, Ni/ZrO₂, Ni/ZnO-ZrO₂ （Zn:Zr=1:1） catalysts which were prepared byCodeposition method for ethanol steam reforming to hydrogen production, theselectivity to hydrogen over the un-reducted catalysts are higher generally than thatover the reduced catalysts. The ability of resistance to carbon deposition of theZnO-ZrO₂ and Ni/ZrO₂ un-reduced is stronger than that of the reduced.but the NZncatalyst is reversed.更多还原