화학공학소재연구정보센터
Separation Science and Technology, Vol.47, No.14-15, 2166-2176, 2012
Nitrophenol Hydrogenation Using Pd Immobilized on Ionic Liquid-Alginate Spherical Resins
Alginate was used for the immobilization of an alkylphosphonium ionic liquid (IL). The IL-alginate resin served for Pd(II) binding from HCl solutions. After chemical reduction of Pd(II), the composite was tested for the hydrogenation of nitrophenols (NPs) and 4-nitroaniline (4-NA) using sodium formate or formic acid as the hydrogen donor (HD) in batch system. The influence of agitation speed, particle size, type, and concentration of HD and pH has been evaluated for 2-NP, 3-NP, 4-NP, and 4-NA (into 2-aminophenol, 2-AP, 3-AP, 4AP and p-phenylenediamine, respectively). Agitation speed does not interfere on hydrogenation kinetics: the film diffusion is not the rate limiting step. The pH influences the catalytic efficiency and the kinetics: pH close to 2-3 being better than pH 1. HD concentration does not influence kinetic profiles above 0.25 M. The modeling of kinetic curves depends on experimental conditions: zero-order rate equation at pH 1, and variable order reaction rate or reversible reaction rate for other pHs, depending on HD concentration and type. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science and Technology to view the free supplemental file.