ie1c01376_si_001.pdf (1.53 MB)
Download filePorous Polyurea Supported Pd Catalyst: Easy Preparation, Full Characterization, and High Activity and Reusability in Reduction of Hexavalent Chromium in Aqueous System
journal contribution
posted on 2021-05-26, 18:25 authored by Muhammad
Sohail Bashir, Xubao Jiang, Xingjie Yang, Xiang Zheng KongDeveloping efficient supports for
transition-metal nanoparticles
(M-NPs) to prevent their agglomeration and to facilitate their handling
and recycled use has been a constant objective. Herein, porous polyurea
(PPU) is prepared by simple precipitation polymerization of toluene
diisocyanate through its reaction with water in water–acetone,
followed by Pd(OAc)2 immobilization on a PPU surface to
get Pd(OAc)2@PPU and by Pd(OAc)2 reduction to
get a hybrid composite Pd@PPU with Pd-NPs on a PPU surface. Multiple
characterizations revealed that the porous structure of PPU was retained
in Pd(OAc)2@PPU and Pd@PPU. Pd NPs were well dispersed
on the Pd@PPU surface with a mean diameter of 7.18 nm. Pd@PPU was
used as catalyst for reduction of toxic hexavalent chromium Cr(VI)
to benign trivalent chromium with formic acid as the reducer. A higher
catalytic performance was detected compared to that of reported heterogeneous
catalysts under similar conditions. A slight decrease in catalytic
activity was detected in recycled use of the catalyst, which is ascribed
to CO poisoning, a byproduct in formic acid decomposition. Full regeneration
was obtained by heating the catalyst under N2 atmosphere
for 2 h at 180 °C. This work provides therefore a novel approach
for the preparation of a Pd@PPU catalyst of high performance for Cr(VI)
reduction, featured by low cost, facile synthesis, easy handling,
and reusability.