The most general picture of a heterogeneous catalyst is depicted as a two component system consisting of an active species and a support for the dispersion of the active species. This two component picture becomes even more important when the active species is a precious metal like platinum.
High dispersion of the metal is required and therefore, almost all the heterogeneous catalysts reported in the literature, and those used industrially, are two component catalysts with metal nanoparticles deposited on a high surface area support. This forms the category of heterogeneous catalysts what we refer to as metal-on-support catalysts. We have, however, developed a range of catalysts in which we have successfully incorporated the noble metal in ionic form in the matrix of the support thereby making a solid solution of the noble metal and the support. We refer to such systems as metal-in-support catalysts because the metal is actually present in the support rather than on the support. This structural change brings about vast diﬀerences in the kinetics of the reaction and also alters the reaction mechanism. We have carried out a thorough structural characterization of the catalysts using numerous techniques including XRD, XPS, FT- Raman, FT-IR spectroscopy and TEM analysis to prove the substitution of the metal in the support matrix. The catalysts were tested for a number of gas phase heterogeneous reactions including syn gas reforming, the water-gas shift reaction, catalytic hydrogen combustion and CO oxidation. This talk will draw attention of the audience towards the dependence of the reaction kinetics and mechanism on the identity of the supports for the water-gas shift reaction, thereby rationalizing the idea of metal-in-support catalysis.
1. Deshpande PA, Madras G. AIChE J. 2010;56:2662-2676.
2. Deshpande PA, Hegde MS, Madras G. Appl Catal B: Environ. 2010;96:83-93.
About the speaker
Parag A. Deshpande is a postdoctoral fellow in the Department of Chemical and Biological Engineering at North- western University, USA. He joined the group of Prof Linda J. Broadbelt in April 2011 where he does computational research for design of biomimetic catalysts for CO2 capture. He obtained
his PhD from the Department of Chemical Engineering at the Indian Institute of Science where he worked under the supervision of Prof. Giridhar Madras
for the synthesis of nanocatalysts for reactions of energy and environmental importance. He was the recipient of BMS fellowship oﬀered by Bristol-Myers Squibb, USA, during his doctoral studies. He has published more than 20 papers in international journals including the AIChE journal, Langmuir, ACS Nano, Chemistry of Materials, Journal of Materials Chemistry and Applied Catalysis B: Environmental. His areas of interest include quantum chemistry, solid state chemistry, spectroscopy and catalysis.
All are Welcome.