0.17%PdCl2/SiO2催化剂上乙炔羰基化

Carbonylation of acetylene over 0.17%PdCl2/SiO2 catalyst

采用等体积浸渍法制备了二氧化硅担载的低担载量的钯催化剂0.17%PdCl2/SiO2。研究以二苯基-2-吡啶膦(2-PyPPh2)为配体的0.17%PdCl2/SiO2催化剂对乙炔羰基化合成丙烯酸的催化性能及其影响因素。结果表明:0.17%PdCl2/SiO2催化剂对乙炔羰基化具有良好的催化作用。乙炔羰基化合成丙烯酸的过程与催化剂、2-PyPPh2配体和对甲苯磺酸的用量以及反应温度、时间有关。在考察的压力范围(1~4MPa)内,压力对乙炔的转化率和丙烯酸的收率几乎没有影响;增加2-PyPPh2、催化剂、对甲苯磺酸的用量和反应时间,有利于乙炔的转化和丙烯酸收率的提高;反应温度低于50℃,升高温度有利于乙炔的转化和丙烯酸收率的提高,反应温度高于50℃,升高温度导致乙炔的转化和丙烯酸的收率降低。当催化剂/乙炔的质量比为0.0026,2-PyPPh2配体的质量浓度为6mg/L,对甲苯磺酸的质量浓度为10mg/L,反应温度50℃,反应时间2h,反应压力1.1MPa(乙炔分压0.1MPa)时,乙炔的转化率达到88%,丙烯酸的收率达到87%。

The silica supported palladium catalyst 0.17%PdCl2/SiO2 with low Pd loading was prepared by incipient wetness impregnation method. The catalytic performance of the catalyst 0.17%PdCl2/SiO2 with 2-(diphenylphosphino)pyridine (2-PyPPh2) as ligand in carbonylation of acetylene to acrylic acid was evaluated, and the effects of various reaction parameters such as the dosage of catalyst, the concentrations of 2-PyPPh2 and p-toluenesulfonic acid and the temperature, reaction pressure and time of reaction on the reaction were investigated. The results showed that the catalyst 0.17%PdCl2/SiO2 had good catalytic effect on carbonylation of acetylene, and the dosages of catalyst, 2-PyPPh2 and p-toluenesulfonic acid and the reaction temperature and time affected the reaction. Within the pressure range of 1-4MPa, the pressure had little effect on the conversion of acetylene and the yield of acrylic acid;increasing the amounts of 2-PyPPh2, catalyst, p-toluene sulfonic acid and reaction time was beneficial to the conversion of acetylene and the yield of acrylic acid;when the reaction temperature was lower than 50℃, the increase of temperature was beneficial to the conversion of acetylene and the yield of acrylic acid, however, when the reaction temperature was higher than 50℃, the conversion of acetylene and the yield of acrylic acid decreased with the increase of temperature. When the mass ratio of catalyst to acetylene was 2.6%, the concentrations of 2-PyPPh2 ligand and p-toluene sulfonic acid were 6mg/L and 10mg/L, respectively, the reaction temperature, time and pressure were 50℃, 2h and 1.1 MPa, respectively, the conversion of acetylene and the yield of acrylic acid reached 88% and 87%, respectively.