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甲浸渍法将 Ni~(2+)负载到含 Pr~(3+)的γ-Al_2 O_3 载体上得到的 Ni/Pr~(3+)-γ-kl_2 O_3 催化剂,对 CO 加氢甲烷化的活性明显高于 Ni/γ～Al_2 O_3。在常压、260℃、H_2/CO=3.5、空速6100时~(-1)的实验条件下,甲烷时空收率提高约50倍。最适宜镨含量为1w%,且添加 Pr~(3+)后不改变 Ni/γ-Al_2 O_3 上 CO 加氢甲烷化反应的机理。经 XRD、TEM、SEM、TPR 及改变催化剂制法等实验说明,Pr~(3+)先与载体γ-Al_2 O_3 发生相互作用,即 Pr~(3+)被γ-Al_2 O_3 稳定,减少或阻碍γ-Al_2 O_3 再与 Ni~(2+)离子发生化学作用生成 NiAl_2 O_4。结果催化剂表面“自由”NiO 较多,可在较低温度(310℃)下还原。还原后,表面富 Ni,故可提高 CO 甲烷化的活性。
The Ni / Pr ~ (3 +) - γ-kl_2 O_3 catalyst supported Ni ~ (2+) on the γ-Al 2 O_3 support containing Pr ~ (3+) Activity was significantly higher than Ni / γ ~ Al 2 O 3. Under the conditions of atmospheric pressure, 260 ℃, H 2 / CO = 3.5 and airspeed of 6100 ~ (-1), the space time yield of methane increased about 50 times. The optimum praseodymium content is 1w%, and the mechanism of CO hydromethanation on Ni / γ-Al 2 O 3 is not changed after adding Pr 3+. The experimental results of XRD, TEM, SEM, TPR and modified catalyst preparation showed that Pr 3+ firstly interacted with the carrier γ-Al 2 O 3, that is, Pr 3+ was stabilized and reduced by γ-Al 2 O 3 Hinder γ-Al 2 O 3 and then react with Ni 2+ ions to form NiAl 2 O 4. As a result, the catalyst surface was “free” with much NiO and could be reduced at a lower temperature (310 ° C). After reduction, the surface of Ni-rich, it can increase CO methanation activity.