Characteristic of polymer-supported acid,base and transition metal complex catalysts

Abstract

Polymer-supported sulfonic acid, pyridine, and ruthenium catalysts have been prepared and their reaction characteristics were investigated. The catalytic activities of sulfonated macroporous poly(styrene-divinylbenzene) beads in 1-butene isomerization were investigated through a model concerning the effect of the distribution and concentration of the sulfonic acid groups. The reaction rate constants increased nonlinearly with increasing the sulfonic acid group concentration and the order of nonlinear power dependence was about 2.4. The values of effectiveness factors of the microparticles in the macroporous resin catalysts with 40\% and 50\% DVB ranged from 0.1 to 0.3. The diffusivities were $10^{-13}$ and $10^{-14}$ $cm^2$/sec for 40\% and 50\% DVB, respectively. The result showed that the major reaction arena was the pore space between the microparticles. Poly(4-vinylpyridine) resin beads containing pyridine moiety were prepared and their catalytic activities were investigated and compared with those of homogeneous counterpart in the esterification of acrylic acid with epichlorohydrin to give 3chloro-2-hydroxyacrylate. In homogeneous catalysis, the overall orders to reactants and catalyst was 2.5: 1.5 for reactants and 1 for catalyst. The activity increased with increasing dielectric constant of solvent. In the esterification using poly(4vinyl pyridine) resins, the activity increased with increasing dielectric constant of solvent and decreasing degree of crosslinking. Also, the activity increased with increasing surface area and hydrophilicity of polymer matrix in porous catalysts. Polymer-supported ruthenium catalyst was prepared by anchoring $RuCl_2(PPh_3)_3$ onto the phosphinated polystyrene bead. The polymer-supported ruthenium catalyst could be reused several times with only small loss of catalytic activity in the isomerization of 1-hexene. The activity rather increased during the few initial runs. In both homogeneous and heterogenized catalysts, an ...