锆对低温液相合成甲醇Cu-Cr催化剂性能的影响

用络合共沉淀法制备了Cu Cr和Cu Cr Zr低温液相合成甲醇催化剂,其比表面积分别达到了77. 9和113. 2m2 /g.在5. 5MPa、383和423K的条件下,用间歇式反应釜考察了催化剂的活性和选择性,并用化学分析的方法测定了反应后溶液中钠化合物含量的变化.结果表明, Cu Cr Zr的活性明显高于Cu Cr,其甲醇的选择性则略有下降;同时,由反应后的钠化合物分析发现, Cu Cr Zr催化体系在423K反应后,溶液中甲酸钠的浓度降低,导致催化体系失活的甲醇钠转化为甲酸钠的反应被彻底抑制.

The Effect of Zirconia on the Performance of Cu-Cr Catalyst for Low Temperature Methanol Synthesis Slurry Phase

Cu-Cr and Cu-Cr-Zr catalysts for the low temperature methanol synthesis slurry phase, with the surface area of 77.9 and 113.2 m~2/g respectively, were prepared by the co-precipitation approach. The activity and selectivity of these catalysts were evaluated in a stainless steel autoclave at 5.5 MPa and at different temperatures of 383 and 423 K separately. It was found that the activity of Cu-Cr-Zr catalyst was obviously higher than that of Cu-Cr catalyst, whereas the methanol selectivity of Cu-Cr-Zr catalyst was a little lower. The concentration of sodium compounds in the solution after reaction was also measured. The results showed that the concentration of sodium formate after reaction is much lower than that before reaction, which is quite different from the observations from the Cu-Cr catalyst previously. This implies that the conversion of sodium methoxide to sodium formate has been completely suppressed in the presence of zirconia in Cu-Cr-Zr catalyst. This finding is more beneficial to improve the performance of Cu-Cr catalyst and to increase the life of catalyst system as well.