负载型水相膦铑配合物催化剂上丙烯氢甲酰化制了醛

Hydroformylation of Propene to Butyl Aldehydes over Supported Aqueous-Phase Rh Catalysts

用连续流动加压微反－色谱装置评价了负载型水溶性膦铑催化剂对丙烯氢甲酰化制了醛的反应活性，结果表明，催化剂活性与体系中水含量密切相关，适量的水可使催化剂活性明显提高，原位红外光谱考察结果显示，当催化剂吸附ＣＯ时在２０４０、２０１２、１９０１ｃｍ－１等处出现一系列可归属于可逆吸附ＣＯ物种的伸缩振动带；通入原料气丙烯／ＣＯ／Ｈ２时，很快可观测到～１７１４ｃｍ－１附近的醛基吸收峰．实验结果表明，水溶性膦铑配合物负载到固体表面后，在载体表面与体系中微量水形成液膜，于气／液膜（固）界面可能有利于丙烯氢甲酰化配位络合催化循环的进行．

Hydroformylation of propene to butyl aldehydes over supported aqueousphase Rh catalysts has been investigated in a fixed-bed reactor-GC system. The effects of the process parameters such as ratio of L (ligand)/Rh; type of support; reaction pressure and temperature as well as the water content in feedstream are studied. The feed rate of water vapor;which is introduced by bubbling feed-gases(C3H6/CO/H2) through a bubbler containing water with adjusted temperature; is crucial for catalyst performance. The results indicate that the formation of the liquid film with a proper water content on the SiO2 surface is the key factor for the dispersion and migration of the Rh complexes. In-situ IR spectroscopic investigation showed that when CO was admitted to the catalyst surface; several reversible IR bands at 1901; 2012; and 2040 cm-1 have been observed; in addition to y(co) ￣ 1980 cm-1 for the absorption of Cumplex HRh (CO) (TPPTS)3. The IR band of butyl aldehydes at ￣ 1714 cm-1 can be immediately observed when C3H6/CO/H2 was induced into IR cell. These experimental results strongly suggest that the structure of complexes is stablilized during immobilization and the hydroformylation occurs on the interface of two immisible phase consisted of feed gas and liquid film.