Impact of our Research
Surface hydroxyl-based bifunctional catalysts: Many organic reactions that are of high relevance in the preparation of pharmaceutical drugs and dyes are carried out in mutiple steps. There are many organic synthesis, which are carried out in multiple steps. Sometimes, these steps are catalyzed by acidic and sometimes by basic. For an efficient conversion, these steps have to be carried out individually following separation and purification steps, consuming additional solvents, energy, delay, loss of yield and higher cost. Using the metal oxyhydroxides, it is possible to combine such steps in a single plot. Although this work hasn't found any immediate application, it opened doors to many new applications in multifunctional catalysis. In this work, we discovered a catalyst that can carry out such reaction steps in one pot without having to separate and purify at the end of each step. This can therefore save energy and the use of polluting solvents. As a result, this is a contribution to green chemical synthesis and may hopefully reduce the cost of the process. Technically, the catalyst must have multiple types of active sites coexisting on the surface. We showed for the first time that a class of materials called metal oxyhydroxides can act as acidic and basic catalyst. As metal hydroxides condense to form metal oxides, there are a range of intermediate compounds called metal oxyhydroxides. These have abundant surface hydroxyl groups on the surface. We showed for the first time that these hydroxyl groups can behave as acidic and basic groups at the same time.
To know more, read our works: D. Vernekar et al Journal of Catalysis (2019), D. Vernekar et al ACS Catalysis, (2021), D. Vernekar et al Catalysis Science and Technology (2015, 2019)
O-vacancy mediated chemical transformations: In crystalline metal oxides, metal and oxide ions are placed in definite positions a sper their crystal structures. Howveer, it is a natural phenomenon that sometimes these atoms are missing from their expected locations. A missing oxide ion is called oxide vacancy which imparts new defect energy levels that can affect the electron transfers with the reactants. We have shown that missing O atoms in metal oxides are very reactive and can be used to carry out organic reactions called nitro reduction and ethylene oxidation.
a) Nitro-reduction: These reactions are normally used to prepare pigments and pharmaceutical products. Importantly, these reactions are normally carried out using expensive Palladium metal. Our discovery makes it possible to carry out the reactions at one hundredth of the cost using copper. This could bring down the cost of medicines!
To know more, read our works: K. Rajendran et al ChemCatChem (2023, 2024), K. Rajendran et al The Journal of Physical Chemistry C (2023), Applied Catalysis B: Environmental (2021).
Available for commercialization: The process of making amino-heterocycles from nitro-heterocycles using non-noble metal catalysts, IIT Palakkad, IN202141037847.
b) Ethylene oxidation: Ethylene oxidation is important for food storage applications. We have developed catalysts that can oxidize ethylene to CO2 at low temperatures (5 oC). Applications of these materials can be useful in controlled atmosphere technologies and improve the shelf life of the agricultural produce.
Available for commercialization: Method of preparation of metal oxide catalyst for oxidation and a process thereof, IIT Palakkad, App No. 202541042350, Filed on 30 April 2025, Publication date 30 May, 2025.