摘要
研究了以水溶性PdCl2(TPPTS)2为催化剂,在水/有机物两相体系中,添加TPPTS、CTAB、PVA、明胶和碳酸钠对柠檬醛加氢反应及催化剂稳定性的影响.添加配体TPPTS、明胶或表面活性剂CTAB有利于减少钯黑的形成,但会引起催化活性的降低;而添加PVA和Na2CO3,虽然都不能抑制钯黑的形成,但后者的添加会明显提高加氢速度;发现,明胶加碳酸钠的体系不仅可以稳定催化剂的活性物种,避免钯黑的析出,而且催化反应的转化率及选择性都较高.
おhe stability of the watersoluble PdCl2(TPPTS)2[TPPTS=P(mC6H4SO3Na)3 ] catalyst system was studied in hydrogenation of citral. Several additives were introduced into the biphasic catalytic system for stabilization of the palladium complex active species in water. The addition of surfactant CTAB, gelatin or ligand TPPTS was favorable to the reducing of Pd black formation, but the catalytic activity was decreased with increasing their concentrations. The addition of PVA or Na2CO3 does not inhibited the formation of Pd black, however, the addition of Na2CO3 resulted in the obvious increase of hydrogenation rate and selectivity. We found that the mixed additives consisting of TPPTS、 Na2CO3 and CTAB were satisfactory for maintaining the higher conversion and selectivity, but the stability of the catalyst system was not very good and more Pd black was formed after five cycles. The higher conversion and selectivity could be kept by proper combination of Na2CO3 and gelatin, and the formation of Pd black could be avoided also.
出处
《分子催化》
EI
CAS
CSCD
北大核心
1998年第3期167-174,共8页
Journal of Molecular Catalysis(China)
关键词
水溶性
钯配合物
加氢
柠檬醛
催化剂
Watersoluble palladium complex, Hydrogenation, Citral, Catalyst stability, Gelatin