John R. Monnier
301 Main Street
University of South
Columbia, SC 29208
John R. Monnier
My research group focuses on heterogeneous catalysis, ranging
from rational catalyst design and synthesis to characterization
and evaluation. Current interests are in the design and
synthesis of novel bimetallic catalysts for the selective
transformation of hydrocarbons to higher value chemicals
and for higher output PEM fuel cells. Bimetallic catalysts
afford great opportunities for changing performance, either
by changing the catalyst surfaces into ensembles of catalytic
sites that permit only selected reaction pathways, modifying
the electronic properties of the catalytic surface sites,
or by introducing bifunctionality to the active surface
by placing different catalytic metals in contiguous proximity.
Bimetallic catalyst synthesis is often carried out by either
simultaneous co-impregnation of both metal salts onto the
catalyst support or by successive steps of metal salt addition.
For either of these preparative methods, it is virtually
impossible to ensure formation of only bimetallic particles;
rather, formation of separate metallic particles of both
metals can and does occur. Thus, it is very difficult to
characterize such catalytic systems, and even more difficult
to correlate catalyst performance with bimetallic catalyst
composition. Our laboratory uses electroless deposition
( ED ), whereby a controlled chemical reaction is used to
deposit a metal salt onto a catalytic metal site that has
been activated by a reducing agent. The process may be
either catalytic ( deposition of the metal salt [ metal A+ ]
from solution onto the pre-existing metal [ metal B° ] on
the support ) or autocatalytic ( deposition of the metal
salt [ metal A+ ] onto the just reduced, deposited metal
[ metal A° ] ), depending on the nature of the activated
metal site and the reducing agent. In principle, ED should
result in the selective deposition of the secondary metal
onto a metallic surface with no formation of isolated crystallites
of the secondary metal on the catalyst support. Perhaps
most importantly, ED is an industrially-relevant process
that can be applied to a wide range of metals. We have
prepared a large number of bimetallic catalysts using electroless
deposition. Those supported on carbon, such as Pt-Co, Pt-Pd,
and Pt-Rh have been tested as electrocatalysts for PEM fuel
cells, while silica-supported compositions such as Ag-Pt,
Au-Pd, and Cu-Pd have been evaluated for traditional catalytic
reactions such as selective epoxidation of olefins, selective
oxidation of biomass molecules (such as glycerol), and selective
hydrogenation of multi-functional olefins. Reactions are
conducted in either automated, single-pass plug flow reactors
( six in all ) or two high pressure batch or stirred tank
reactors. Our research projects are currently funded by
NSF, DOE, and several industrial companies.
- Ph. D., University of Wisconsin-Milwaukee ( 1978 )
- M. S., University of Wisconsin-Milwaukee ( 1972 )
- B. S., St. Ambrose University, Davenport, IA ( 1970 )
- J. Rebelli,, A.A. Rodriguez, S. Ma, C.T. Williams, J.R. Monnier,
"Preparation and Characterization of Silica-Supported, Group
IB-Pd Bimetallic Catalysts Prepared by Electroless Deposition
Methods," Catal. Today, 160, 170 ( 2011 ).
- K. Punyawudho, D.A. Blom, J.W. Van Zee and J.R. Monnier,
"Comparison of different methods for determination
of Pt surface site concentrations for supported Pt electrocatalysts,"
Electrochim. Acta, 55, 5349 ( 2010 ).
- M. Ohashi, K.D. Beard, S. Ma, D.A. Blom, J. St-Pierre,
J.W. Van.Zee, and J.R. Monnier, "Electrochemical and
Structural Characterization of Carbon-Supported Pt-Pd Bimetallic
Electrocatalysts prepared by Electroless Deposition,"
Electrochimica Acta, 55, 7376 ( 2010 ).
- M.T. Schaal, J. Rebelli, H.M. McKerrow, C.T. Williams,
and J.R. Monnier, "Effect of liquid phase reducing
agents on the dispersion of supported Pt catalysts,"
Appl. Catal. A: General, 382, 49 ( 2010 ).
- K.D. Beard, D. Borelli, A.M. Cramer, D. Blom, J.W. Van
Zee, and J.R. Monnier, "Preparation and structural
analysis of carbon-supported Co core/Pt shell electrocatalysts
using electroless deposition methods," ACS Nano, 3, 2841( 2009 ).
- M.T. Schaal, A.C. Pickerell, C.T. Williams, and J.R. Monnier,
"Characterization and evaluation of Ag-Pt/SiO2 catalysts
prepared by electroless deposition," J. Catal.,
254, 131 ( 2008 ).