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Volume 3, Issue 2 (Suppl)
Trends in Green chem
ISSN: 2471-9889
Environmental & Green Chemistry 2017
July 24-26, 2017
Page 126
5
th
International Conference on
6
th
International Conference on
July 24-26, 2017 Rome, Italy
Environmental Chemistry and Engineering
Green Chemistry and Technology
&
Lignin into aromatics: Bridging homogeneous and heterogeneous catalysis
Changzhi Li
Dalian Institute of Chemical Physics - CAS China
T
he development of efficient catalytic conversionof lignin into aromatic chemicals remains an important challenge in catalysis
due to the amorphous carbon-based inactive property and highly heterogeneous nature of lignin. Potential strategies for
the production of aromatics from lignin need to address the issues of lignin solubility as well as of the selective cleavage of
the aryl ether bonds. In this lecture, we will discuss our progress in catalytic lignin valorization relating to aforementioned
two aspects. In the first part, we will report the selective cleavage of aryl ether in lignin to afford monophenols over tungsten
carbide (W
2
C) catalysts. The activation mechanisms of different aryl ether bonds over W
2
C are deeply explored. On the other
hand, synergistic effect between W
2
C and a second metal, the effect of the monomer structure on the catalytic performance,
and the catalyst stability under liquid phase conditions will be discussed as well. In the second part, selective cleavage of lignin
to aromatic compounds catalyzed by methyltrioxorhenium (MTO) without any oxidant (e.g. H
2
O
2
) and reducing agent (e.g.
H
2
) is proposed. The introduction of ionic liquids supplies a homogeneous platform which allows the process conducting
under mild condition. Microwave irradiation could accelerate the reaction rate and significantly increase the activity. Under
optimized conditions, a series of lignin β-O-4 model compounds could afford guaiacol as the primary product with the yields
higher than 67%. The possible mechanisms for degradation of lignin is proposed based on IR spectroscopy and NMR results.
licz@dicp.ac.cnDesigning green catalysts using earth-abundant metals: solving the “how-to” and “why” questions
using quantum chemistry approaches
Dequan Xiao
University of New Haven, USA
I
t is a general challenge to design highly active or selective green catalysts using earth-abundant metals. We demonstrated
an effective computational approach to deterministically search for optimal binding sites on Cu (100) surface (for catalytic
hydrogenation) through the doping of Fe and/or Zn using the inverse molecular design methods. A stable Zn-doped Cu (100)
surface was found with optimal binding affinity to H-atoms. We understood the electronic structure cause of the optimal
binding sites using orbital-specific binding energy analysis, a new quantum chemistry analysis method here. Overall, we found
that the Zn atomic orbitals show less participation in the binding event of H-atoms than the Cu atomic orbitals. In particular,
compared to the 3d-orbitals of surface Cu atoms, the 3d-orbitals of surface Zn-atoms show less binding energy contribution
and participation, and are much less influenced by the electronic couplings of the media Cu atoms. Our study provides valuable
green chemistry insights for the design of green catalysts using earth-abundant metals. Our designed Cu-based earth-abundant
alloys may be used for important catalytic hydrogenation applications such as lignin degradation or CO
2
transformation.
DXiao@newhaven.eduTrends in Green chem, 3:2
DOI: 10.21767/2471-9889-C1-003