摘要
采用浸渍法分别以MCM-41,Al2O3和SiO2为载体制备了不同镍负载量的甲烷化催化剂,并在连续流动固定床反应装置上对其甲烷化催化活性进行了评价。研究结果表明,与Ni/Al2O3和Ni/SiO2相比,相同镍负载量的Ni/MCM-41催化剂具有更好的催化活性。同时研究了Ni含量对于Ni/MCM-41催化剂催化活性的影响,发现随着Ni含量的增加,CO转化率和CH4收率逐渐升高,并且在Ni含量大于10%(质量分数)以后趋于稳定。在n(H2):n(CO)=3:1、反应压力1.5 MPa、反应温度350℃及质量空速12000 ml·h-1·g-1的反应条件下,10%Ni/MCM-41催化剂CH4选择性达到94.9%,CO转化率接近100%。在100 h催化活性稳定性试验中,10%Ni/MCM-41催化活性无明显下降,表现出良好的催化活性稳定性。采用X射线衍射(XRD)、氮气物理吸附(BET)、热重分析(TG)及氢气程序升温还原(H2-TPR)等技术手段对催化剂进行了表征,结果表明Ni颗粒大小是影响Ni/MCM-41催化剂催化活性的主要因素。
Nickel based catalysts with different nickel contents were prepared by the impregnation method with MCM-41, A1203 and SiO2 as supports, and catalytic performance was studied in a fixed-bed reactor for the production of synthetic natural gas （SNG）. Compared with the Ni/A1203 and Ni/SiO2 catalysts, Ni/MCM-41 catalysts with the same nickel content of 10%（mass） showed better catalytic performance with high CO conversion of 100% and CH4yield of 94.9% at 350℃ under 1.5 MPa with 3：1 molar ratio of H2 to CO and a weight hourly space velocity （WHSV） of 12000 ml ·h^-1·g^-1. The effect of Ni loading on catalytic performance of Ni/MCM-41 catalysts was also investigated. Catalytic activity increased with increasing Ni loading and kept stable with Ni loading of above 10%（mass）. 10% Ni/MCM-41 catalyst also exhibited excellent catalytic activity and stability in the catalytic stability test. The catalysts were characterized with X-ray diffraction （XRD）, N2 physisorption measurements, thermo gravimetric analysis （TG） and H2 temperature-programmed reduction （H2-TPR）. Ni particle size could obviously affect the catalytic performance of Ni/MCM-41 catalysts. Ni/MCM-41 catalyst with 10%（mass） nickel content and appropriate nickel particles of 15.5 nm exhibited good catalytic performance with almost 100% CO conversion and 94.9% CH4 yield.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2014年第1期160-168,共9页
CIESC Journal
基金
国家自然科学基金重点项目(U1203293)~~
