title: Immobilization of nanoscale Fe0 in and on PVA microspheres for nitrobenzene reduction.
abstract: In this study, nanoscale Fe(0) was immobilized in and on poly(vinyl alcohol) (PVA) microspheres by the inverse suspension crosslinked method. Two different sizes of Fe(0)/PVA microspheres were synthesized in the presence and absence of dispersant. The chelating action between Fe(2+) and PVA was identified by Fourier transform infrared and X-ray photoelectron spectroscopy. The morphology and distribution of the obtained Fe(0)/PVA microspheres were characterized by environmental scanning electron microscope, energy-dispersive X-ray spectrometry, and X-ray diffraction. Nanoscale Fe(0) particles were mostly dispersed over the surface of the microspheres. They were distributed more homogeneously on the surfaces of Fe(0)/PVA microspheres with diameter of 600-700 microm than those with diameter of 10-12 microm. The nitrobenzene (NB) reduction reactions followed pseudo-first-order kinetics. The normalized surface rate constants (k(SA)) values were determined to be 0.162 L h(-1)m(-2) for L-Fe(0)/PVA microspheres, 0.098 L h(-1)m(-2) for S-Fe(0)/PVA microspheres, and 0.023 L h(-1)m(-2) for nanoscale Fe(0) particles. Furthermore, with the analysis of the products by GC/MS, possible reductive pathways of NB by Fe(0)/PVA microspheres were suggested. The recovery rates of iron in microspheres were determined to be 81.17% for large Fe(0)/PVA and 60.31% for small Fe(0)/PVA.
authors.affiliation: College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, PR China.
authors.forename: Xue
authors.initials: X
authors.lastname: Bai
authors.forename: Zheng-Fang
authors.initials: ZF
authors.lastname: Ye
authors.forename: Yan-Zhi
authors.initials: YZ
authors.lastname: Qu
authors.forename: Yan-Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Zhong-You
authors.initials: ZY
authors.lastname: Wang
mesh_terms: D002614:Chelating Agents; D007501:Iron / Q000737:chemistry*; D008863:Microspheres; D053758:Nanoparticles; D009578:Nitrobenzenes / Q000737:chemistry*; D010084:Oxidation-Reduction; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D019163:Reducing Agents
chemical_list: D002614:Chelating Agents; D009578:Nitrobenzenes; D019163:Reducing Agents; D011142:Polyvinyl Alcohol; D007501:Iron; C036077:nitrobenzene