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以骨架NiMo以及与氧化物物理混合,考察了其在连续固定床反应器中无外加氢气条件下的丙三醇一锅法重整–氢解制1,2-丙二醇(1,2-PDO)的性能.研究发现,骨架NiMo自身催化活性高,但对1,2-PDO的选择性一般.当将其与MgO,SiO2,Al2O3,HZSM-5,TiO2,ZrO2或CeO2机械混合时,丙三醇转化率和1,2-PDO选择性均发生下降.但当与ZnO物理混合时,催化活性和选择性均有所提高,1,2-PDO得率可达52.0%,优于贵金属催化剂在该一锅法反应中得到的结果.物理混合的ZnO与骨架NiMo之间这种独特的协同作用,归因于重整过程中产生的CO2在ZnO上发生化学吸附,原位增强了ZnO的路易斯酸性.这不仅促进了丙三醇在ZnO上脱水生成中间产物丙酮醇,也促进了丙酮醇在骨架NiMo上加氢生成1,2-PDO.
NiMo as a framework and physically mixed with oxides were investigated for one-pot reforming of 1,2-propanediol (1,2-PDO) with glycerol in a continuous fixed-bed reactor without hydrogen addition. The results show that the framework NiMo has high catalytic activity, but its selectivity to 1,2-PDO is generally high. When it is mechanically mixed with MgO, SiO2, Al2O3, HZSM-5, TiO2, ZrO2 or CeO2, The conversion of alcohol and the selectivity of 1,2-PDO decreased.However, the catalytic activity and selectivity were both improved when mixed with ZnO physically, the yield of 1,2-PDO was 52.0%, which was better than that of noble metal catalyst The result of this one-pot reaction is that this unique synergy between the physically-mixed ZnO and the framework NiMo is attributed to the chemisorption of CO2 produced during the reforming on ZnO and the in situ ZnO-enhanced Lewis Which not only promoted the dehydration of glycerol on ZnO to generate the intermediate product acetol but also promoted the hydrogenation of acetol on NiMo skeleton to produce 1,2-PDO.