Ligand assisted molecular electrocatalysis and molecular charge storage

Abstract

The global energy crisis due to the extensive use of fossil fuels has already become a ubiquitous problem, making the domain of renewable energy conversion a hot research topic for the global scientific community. Electrochemical transformation via electrocatalysis has become an area of research focus because of its potential to convert abundant feedstocks into value-added products. This has in turn led to the design and development of various metal-based and molecular electrocatalysts. Molecular electrocatalysts such as phthalocyanines and porphyrins have gained a lot of attention mainly because of their superior chemical and thermal stability and highly flexible optoelectronic nature. In molecular electrocatalysts, it is well known that the fate of an electrochemical reaction is majorly dictated by the central metal ion. In these lines, the primary aim of my thesis is to unravel the role of ligand in electrocatalysis pertaining to challenging electrochemical transformations.

In the first chapter the role of ligand is elucidated by changing the isomerism of the ligand surrounding the same central metal ion, and it is observed that this kind of regioisomerism majorly influences the reaction kinetics, however the mechanism remains unaltered. Subsequently, the nature of the ligand is explored for tuning the mechanistic pathways in oxidative electrocatalysis and a counterintuitive electrocatalysis was observed, which was attributed to proton charge assembly surrounding the ligand. In the subsequent chapter, this proton charge assembly is exploited for tuning the charge storage in the electrical double layer. Following these lines, the ubiquitous oxygen reduction reaction (ORR) is probed and a change in the mechanistic pathway is elucidated.