Res. Chem. Intermed.
, Vol. 32, No. 3–4, pp. 373–385 (2006)
Also available online - www.vsppub.com
Active control of catalysis and product selectivity
Department of Applied Chemistry, Graduate School of Science and Engineering,
Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152, Japan
Received 28 December 2004; accepted 25 February 2005
Abstract—A new concept to control catalysis and catalytic reaction through partial oxidation of
alkenes with O
is described. Oxidation of alkenes was studied by alkene/Pd-anode/H
fuel cell (FC). An idea based on electrocatalysis and electrochemical reactions to
control reaction rates and product selectivity was proposed and proven through the oxidation of
propylene, Wacker and π-allyl oxidation. The oxidation rate and the product selectivity to the Wacker
and the π-allyl oxidations could be controlled by changing electrode potentials. We could active
control oxidation states of Pd on the anode, Pd(II) or Pd(0), during the oxidation from outer circuit.
The oxidation states of Pd on the anode decided the product selectivity.
Keywords: Catalysis control; partial oxidation; fuel cell; Wacker oxidation; π-allyl oxidation.
Control of reaction rate and product selectivity is a very attractive subject for
future chemical synthesis and process. It is not easy to control reaction rates and
product selectivities in conventional catalytic reactions. In order to develop new
control methods, new catalysis concepts and catalysts are necessary. An idea and
a veriﬁcation to control catalysis and reactions, based on electrochemical reactions,
are described in this short review.
-fuel cell (FC) is a device for converting the change in the free
energy of a chemical reaction to electricity through electrochemical cell reactions.
Electrochemical oxidation of H
occurs at the anode (H
) and the reduction of O
O takes place at the cathode
O). The net reaction is the formation of water from
O). Conversely, the oxidation of H