Kothandaraman Ramanujam

Bio: Kothandaraman Ramanujam is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Catalysis & Chemistry. The author has an hindex of 12, co-authored 67 publications receiving 544 citations. Previous affiliations of Kothandaraman Ramanujam include Michigan State University.

A High Voltage Organic Redox Flow Battery with Redox Couples O2/Tetrabutylammonium Complex and Tris(4-bromophenyl)amine as Redox Active Species

Abstract: Redox flow batteries (RFBs) are considered a vital part of the energy storage system for storing the energy generated from the renewable energy sources such as wind and solar. Limited by the water electrolysis potential window, the aqueous RFBs exhibit low energy density (<25 Wh L−1). In this context a non-aqueous organic solvent based RFB system is very attractive as it offers avenue to expand the operating potential window beyond 1.23 V, which has a direct impact on the RFB's energy and power densities. In this study, new redox systems based on tris(4-bromophenyl)amine (4-Br-TPA) and oxygen saturated N,N-dimethylformamide (DMF) containing tetra-n-butylammonium hexafluorophosphate (TBAPF6) are utilized as catholyte and anolyte respectively. Here, TBAPF6 performs dual role, both as supporting electrolyte and a stabilizer of superoxide anion radical.

Selective Sensing of the Biotinyl Moiety Using Molecularly Imprinted Polyaniline Nanowires

Abstract: A chemosensor for selective recognition of biotinyl moiety has been devised using electropolymerized film and tested against selective biotinylated targets. The sensor comprises biotin molecularly ...

Electrochemical Determination of Paraquat Using Gold Nanoparticle Incorporated Multiwalled Carbon Nanotubes

Abstract: The present work focuses on electrochemical estimation of the herbicide, paraquat using Au nanoparticle incorporated multi-walled carbon nanotube (AuNP-MWCNT). The catalyst was synthesised and characterised using physical characterization techniques like HRSEM, HRTEM, Raman spectroscopy, and XRD. The techniques reveal the successful incorporation of Au nanoparticles onto MWCNT and it was utilized for the electrochemical determination of paraquat (PQ). The AuNP-MWCNT modified glassy carbon electrode (AuNP-MWCNT/GCE) was able to detect PQ reversibly using cyclic voltammetric analysis. From the electrochemical tests, it was discovered that the electrode is an efficient catalyst for the effective electrochemical sensing of PQ. Using cathodic stripping square wave voltammetric technique (CSSWV), the sensitivity and limit of detection of the matrix against PQ was evaluated. They were found to be 0.197 mA/µM and 32 nM, respectively in the concentration range of 1.0 µM to 2.0 µM with the regression coefficient value of 0.99. Further, selectivity studies clearly demonstrated that the proposed catalyst was interference-free from other possible foreign molecules. The practical applicability of the electrode was checked in the electrolyte containing real samples and the appreciable recovery was achieved.

Recent Advances in Electrocatalysts for Oxygen Reduction Reaction

Abstract: The recent advances in electrocatalysis for oxygen reduction reaction (ORR) for proton exchange membrane fuel cells (PEMFCs) are thoroughly reviewed. This comprehensive Review focuses on the low- and non-platinum electrocatalysts including advanced platinum alloys, core–shell structures, palladium-based catalysts, metal oxides and chalcogenides, carbon-based non-noble metal catalysts, and metal-free catalysts. The recent development of ORR electrocatalysts with novel structures and compositions is highlighted. The understandings of the correlation between the activity and the shape, size, composition, and synthesis method are summarized. For the carbon-based materials, their performance and stability in fuel cells and comparisons with those of platinum are documented. The research directions as well as perspectives on the further development of more active and less expensive electrocatalysts are provided.

Metal–Organic Frameworks in Heterogeneous Catalysis: Recent Progress, New Trends, and Future Perspectives

Abstract: More than 95% (in volume) of all of today’s chemical products are manufactured through catalytic processes, making research into more efficient catalytic materials a thrilling and very dynamic rese...

Molecularly Imprinted Polymers

Abstract: Molecularly imprinted polymers are synthetic receptors for a targeted molecule. As such, they are analogues of the natural antibody–antigen systems. In this review, after a recounting of the early history of the general field, we specifically focus on the application of these polymers as sensors. In these applications, the polymers are paired with a reporting system, which may be electrical, electrochemical, optical, or gravimetric. The presence of the targeted molecule effects a change in the reporting agent, and a calibrated quantity of the target is recorded. In this review, we describe the imprinted polymer production processes, the techniques used for reporting, and the applications of the reported sensors. A brief survey of recent applications to gas-phase sensing is included, but the focus is primarily on the development of sensors for targets in solution. Included among the applications are those designed to detect toxic chemicals, toxins in foods, drugs, explosives, and pathogens. The application...

Nonprecious Metal Catalysts for Oxygen Reduction in Heterogeneous Aqueous Systems

Abstract: A comprehensive review of recent advances in the field of oxygen reduction electrocatalysis utilizing nonprecious metal (NPM) catalysts is presented Progress in the synthesis and characterization of pyrolyzed catalysts, based primarily on the transition metals Fe and Co with sources of N and C, is summarized Several synthetic strategies to improve the catalytic activity for the oxygen reduction reaction (ORR) are highlighted Recent work to explain the active-site structures and the ORR mechanism on pyrolyzed NPM catalysts is discussed Additionally, the recent application of Cu-based catalysts for the ORR is reviewed Suggestions and direction for future research to develop and understand NPM catalysts with enhanced ORR activity are provided

Durability Investigation of Carbon Nanotube as Catalyst Support for Proton Exchange Membrane Fuel Cell Electrode

Abstract: Abstract Electrochemical surface oxidation of carbon black Vulcan XC-72 and multiwalled carbon nanotube (MWNT) has been compared following potentiostatic treatments up to 168 h under condition simulating PEMFC cathode environment (60 °C, N2 purged 0.5 M H2SO4, and a constant potential of 0.9 V). The subsequent electrochemical characterization at different treatment time intervals suggests that MWNT is electrochemically more stable than Vulcan XC-72 with less surface oxide formation and 30% lower corrosion current under the investigated condition. As a result of high corrosion resistance, MWNT shows lower loss of Pt surface area and oxygen reduction reaction activity when used as fuel cell catalyst support.