Premium
Recyclable plant tannin‐chelated Rh(III) complex catalysts for aqueous–organic biphasic hydrogenation of quinoline
Author(s) -
Mao Hui,
Liao Xuepin,
Zhang Wenhua,
shi Bi
Publication year - 2012
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.3726
Subject(s) - tannin , catalysis , chemistry , chelation , quinoline , aqueous solution , organic chemistry , polyphenol , x ray photoelectron spectroscopy , nuclear chemistry , antioxidant , chemical engineering , engineering , food science
BACKGROUND: Synthetic ligands have conventionally been used for the preparation of homogenous Rh complex catalyst but biomass has rarely been utilized for this purpose. In the present investigation, plant tannins (natural polyphenols) were used as water‐soluble ligands for the preparation of homogenous Rh 3+ complex catalysts. RESULTS: Based on X‐ray photoelectron spectroscopy (XPS) and proton nuclear magnetic resonance (HNMR) analyses, the preparation mechanism of these complex catalysts was proven to involve chelating interactions between Rh 3+ and the adjacent phenolic hydroxyls of plant tannins. As a result, the use of plant tannin promoted aqueous‐organic biphasic interactions and the plant tannin‐chelated Rh 3+ complex catalysts exhibited much higher catalytic activity than commercial Rh complex catalysts in the biphasic hydrogenation of quinoline. Furthermore, the plant tannin‐chelated Rh 3+ complex can be reused three times without significant loss of catalytic activity CONCLUSION: Our experimental results suggested that black wattle tannin (BWT) can be used as water‐soluble ligands for the preparation of highly active and recyclable Rh 3+ complex catalysts. Copyright © 2012 Society of Chemical Industry