乙烯气相醛化负载铑催化剂的加压原位红外光谱研究

应用加压原位红外光谱反应装置 ,在 2 0～ 14 0℃、n(C2 H4) /n(CO) /n(H2 ) =1/1 5 /1 5、1 5～ 2 0MPa条件下 ,考察了乙烯气相醛化制丙醛负载铑催化剂的原位红外光谱。结果表明 ,以Rh(CO) (acac) (PPh3)或RhCl3 作为催化剂母体 ,在过量三苯基膦和合成气的存在下 ,均可生成HRh(CO) (PPh3) 2 及其二聚体 Rh(CO) (PPh3) 2 ] 2 和 /或HRh(CO) 2 (PPh3) 2 及其二聚体〔Rh(CO) 2 (PPh3) 2 〕2 ,这些络合物可组成平衡体系 ,为反应提供催化活性物种 ,保证乙烯醛化反应的连续进行。

In Situ Infrared Study on Supported Rhodium Catalyst for the Vapor-Phase Hydroformylation of Ethylene

Supported rhodium catalysts for vapor phase hydroformylation of ethylene were studied under reaction conditions close to that of industrial production (n(C 2H 4)/n(CO)/n(H 2)=1/1 5/1 5,1 5～2 0 MPa,20～140 ℃).The results indicate that Rh(CO)(acac)(PPh 3) or RhCl 3 as precursor of catalytically active species can be converted to HRh(CO)(PPh 3) 2 and its dimer Rh(CO)(PPh 3) 2] 2 and /or HRh(CO) 2(PPh 3) 2 and its dimerRh(CO) 2(PPh 3) 2] 2 in the presence of excees P(C 6H 5) 3 and syngas.An equilibrium system may be formed from these four complexes,so that the active species for hydroformylation of ethylene can be provided continually.