稀土对铱基甲醇羰基化催化体系性能的影响

Effect of Rare Earth Metals on Carbonylation of Methanol to Acetic Acid over Iridium-Based Catalysts

采用稀土金属碘化物或氧化物对铱基羰基化催化体系进行改性,并考察了改性后的催化体系的羰基化反应活性。实验结果表明,采用稀土金属碘化物对Ir-I催化体系进行改性时,羰基化反应活性均出现明显下降;而采用稀土金属氧化物对Ir-I和Ir-Ru-I催化体系进行改性时,羰基化反应活性明显提高。其中,当采用Nd2O3对Ir-Ru-I催化体系进行改性时,在CH3COOCH3含量10.0%(w)、H2O含量3.9%(w)的条件下,甲醇羰基化反应速率可增至15.5 mol/(L.h)。Ir-Ru-I催化体系经稀土金属氧化物改性后,气相副产物CH4和CO2的平均生成速率增大,液相副产物丙酸的平均生成速率降低。

An iridium-based catalyst system was modified with rare-earth-metal iodides or oxides and their catalytic activities in the carbonylation of methanol were studied. The results showed that the activities were reduced significantly when Ir-I catalyst system was modified with rare-earth-metal iodides but raised obviously when Ir-I and Ir-Ru-I catalyst systems were modified with rare-earth-metal oxides. Especially, when the Ir-Ru-I catalyst system was modified with Nd：O3, under the conditions of CH3COOCH3 content 10.0%（w） and H20 content 3.9%（w）, the carbonylation rate reached 15.5 mol/（L · h）. After the Ir-Ru-I catalyst system was modified with rare-earth-metal oxides, the average yields of gas by-products CH4 and CO2 were improved while the average yield of liquid by-product propionic acid was reduced.