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采用浸渍法制备了四方相ZrO2(t-ZrO2)和单斜相ZrO2(m-ZrO2)负载的Ni含量为10%的催化剂,在连续流动微反装置上考察了Ni/m-ZrO2以及不同温度焙烧Ni/t-ZrO2催化剂的CO甲烷化催化活性.采用N2物理吸附-脱附、H2-TPR、XRD、CO-TPSR及原位漫反射傅里叶变换红外光谱等技术对催化剂进行了表征.结果表明,在CO体积分数为1%,空速为20 000 h-1,常压的反应条件下,当CO转化率为50%时,Ni/m-ZrO2-673和Ni/t-ZrO2-673催化剂的反应温度分别为445 K和488 K,Ni/m-ZrO2-673催化剂的CO甲烷化活性远高于Ni/t-ZrO2-673催化剂.随焙烧温度的升高,Ni/t-ZrO2催化剂的CO甲烷化活性评价显著升高,产生这一现象的原因是在高温焙烧过程中Ni/t-ZrO2催化剂表面的t-ZrO2已转化为m-ZrO2,以m-ZrO2为载体的催化剂因m-ZrO2表面具有较多的配位不饱和O2-碱性中心和配位不饱和Zr4+-O2-位点而表现出高的CO甲烷化活性.
The catalysts with Ni content of tetragonal ZrO2 (t-ZrO2) and monoclinic ZrO2 (m-ZrO2) supported on 10% Ni were prepared by impregnation method. The effects of Ni / m-ZrO2 and different temperature Catalytic CO methanation of calcined Ni / t-ZrO2 catalystThe catalysts were characterized by N2 physisorption-desorption, H2-TPR, XRD, CO-TPSR and in situ diffuse reflectance Fourier transform infrared spectroscopy. The results show that Ni / m-ZrO2-673 and Ni / t-ZrO2- The catalytic activity of Ni / t-ZrO2-673 was much higher than that of Ni / t-ZrO2-673 at 445 K and 488 K. The calcination temperature of Ni / t-ZrO2- The CO methanation activity of the catalyst was significantly increased. The reason for this phenomenon is that the t-ZrO2 on the surface of Ni / t-ZrO2 catalyst has been converted to m-ZrO2 during calcination at high temperature, and the catalyst due to m-ZrO2 The surface of m-ZrO2 has a large number of coordinated unsaturated O2-basic centers and coordinated unsaturated Zr4 + -O2- sites and shows high CO methanation activity.