【摘要】 以异丙叉丙酮（MO）选择性加氢得到甲基异丁基酮（MIBK）作为模型反应,进行了固体催化剂的设计。研究结果表明,大孔径小比表面的浮石是较好的载体,Ni作为主要活性组份对C=C和C=O键有较高的加氢活性,但选择性低,以Cu和Cr对Ni/浮石进行了改性,对Ni/浮石,Ni—Cu/浮石,Ni—Cr/浮石,Ni—Cu—Cr/浮石等催化剂进行了研究。TPD研究表明,Cu可降低H₂,MO,MIBK的吸附量,增加H₂和MO的T_m,降低MIBK的T_m,Cr可增加MO的吸附量,降低H₂,MIBK的吸附量,由于Cu和Cr的协同作用,使MIBK的T_m下降约45℃,热分析研究表明,Ni—Cu—Cr/浮石的还原温度必须大于320℃。SEMS研究表明Cu和Cr增加了催化剂表面的分散度和均匀性,这些结果解释了Ni—Cu—Cr/浮石催化剂对不饱和酮加氢具有较高活性和选择性的原因。更多还原

【Abstract】 A catalyst for the selective hydrogenation of mesityl oxide (MO) to methyl isobutyl ketone (MIBK) was studied. The carrier with large pore size and low surfa-ce area was indispensable. Ni was selected as an active component, because it had high activity for the hydrogenation of C = C and C = O bonds, but the selectivity was low. Ni/pumice was modified by the addition of Cu and Cr, and Ni/pumice, Ni-Cu/pumice, Ni-Cr/pumice and Ni-Cu-Cr/pumice were investigated by TPD, thermoanalysis and scanning electron microscope (SEMS).Results of TPD showed that Ni/pumice modified by Cu decreased the adsorption volume of H2, MO, and MIBK, increased Tm of H2 and MO, and decreased Tm of MIBK; while the modification by Cr increased the adsorption volume of MO and decreased the adsorption volume of H2 and MIBK. Due to the synergistic effect of Cu and Cr, Tm of MIBK went down, by 45℃. Thermoanalysis indicated that the reduction temperature of Ni-Cu-Cr/pumice catalyst had to be higher than 320℃. The dispersity and uniformity of the catalyst were increased by the modification with both Cu and Cr as shown by SEMS. Thus, the high activity and selectivity of Ni-Cu-Cr/pumice for the hydrogenation of unsaturated ketones could be clearly explained.更多还原