Research Projects

Acid catalyzed reactions constitute a major portion of industrial processes for the production of several bulk and fine chemicals. Solid acids are actively sought benign replacement of toxic and corrosive liquid acids as catalysts at commercial scale. Principles of acid strength, its measurement and relevance with respect to the catalytic activity has been well studied by Hammett and his co-workers, which is not the case for solid acids. Conventional Hammett protocols cannot be extended to solid acids, thereby advanced spectroscopic tools like solid-state NMR, DRIFT(FTIR), etc. have been developed lately by the researchers to characterize the acidity, and study the intricate phenomenon involved during chemical transformations over the catalyst surface. However, the catalyst studied are mostly zeolites and for vapor phase reactions. Ion exchange resins, supported heteropoly acids, etc. which are commonly used for liquid phase reactions, have not received much attention. We propose to exploit these modern spectroscopic tools to study their intrinsic acidity (ex-situ), and correlate with its activity for a variety of industrially important chemical reactions. They include, isomerization, esterification, acetalization, aldol condensation, acylation etc. We also plan to perform in-situ NMR and DRIFTS experiments for few short-listed reactions and catalysts to gain insights into reaction mechanism, active chemical intermediates, and effect of solvent, water, temperature, B/L ratio (Bronsted to Lewis Acidity ratio) on the catalytic activity. The motive is to understand the structure-activity correlations in solid acid catalyzed reactions, and select or design catalysts on the basis of it. The supremacy of the best catalysts identified by spectroscopic methods will be verified through batch/continuous kinetic studies and rigorous kinetic model will be proposed. We will also perform DFT-based computational catalysis to support the results.

Solid Acid Catalysis, Acid strength, Solid state NMR, DRIFTS, Solvent/water effect, Rational Catalyst Design