Ni/ZrO2催化剂上甲烷水蒸气重整反应的研究

研究了Ni/ZrO2催化剂对甲烷水蒸气重整制合成气的反应性能。考察了催化剂的还原温度、载体焙烧温度以及反应温度、原料配比和空速等对催化剂性能的影响。利用XRD、TEM、XPS等手段对催化剂的织构形貌进行了表征。研究表明，Ni/ZrO2催化剂用于甲烷水蒸气重整制合成气不仅具有较高的活性，也具有较好的稳定性。水蒸气比增加，CH4转化率增大、CO选择性下降。CH4转化率及CO选择性均随空速增大而下降。使用10%Ni/ZrO2催化剂，在650 ℃、空速1.984×104 h－1、原料气配比H2O∶CH4∶N2=2∶1∶2.67的条件下，获得CH4转化率85%、CO选择性70%的结果。

STUDIES ON STEAM REFORMING OF METHANE OVER Ni/ZrO2 CATALYST

Development of the catalysts with high activity and stability for the methane steam reforming has significant importance for the practical application of the process of nature gas steam reforming in fuel cell. The catalytic performances of Ni/ZrO2 in the steam reforming of methane were investigated in this paper. The influences of the reduction temperatures of the catalyst, calcination temperatures of ZrO2 support, reaction temperature, ratios of feed gas and space velocities on the catalytic performance of Ni/ZrO2 were examined. The structure of the catalyst was characterized by XRD, TEM, XPS and TPR. The experimental results indicate that Ni/ZrO2 catalyst had relatively high activity and stability in the steam reforming of methane. No significant influence was observed on the catalytic activity when the calcination temperatures of the support changed from 550 ℃ to 850 ℃. The catalyst reduced at 550 ℃ showed somewhat higher activity, but a little influence on CO selectivity in the range of reduction temperature from 450 ℃ to 750 ℃. The conversion of methane increased with an increase of H2O/CH4 ratio, while CO selectivity decreased. The conversion of methane and CO selectivity decreased with an increase of space velocity. The result of 85% methane conversion and 70% CO selectivity was obtained over 10% Ni/ZrO2 catalyst under the conditions of 650 ℃, 1.984×104 h－1 and H2O∶CH4∶N2=2∶1∶2.67.