Recent development on metal phthalocyanines based materials for energy conversion and storage applications

Owing to the rapid decline of fossil fuels and related deleterious consequences throughout the globe, energy use is undergoing a significant and dramatic transition into electricity as major power source. The renewable, safe, and reliable alternative energy resources and storage systems are thus very much required for modern society. In this context, H2, O2 and CO2 involving electrochemical energy conversion and storage systems can be regarded as the sustainable way to meet the future energy demand. Nonetheless, the sluggish kinetics of these electrochemical reactions at electrode surface in their corresponding devices is one of the biggest challenges for the development of such technologies. Among various classes of electrocatalysts, MN4-type molecular electrocatalysts, particularly, metal phthalocyanines (MPcs) were found to be potential models to enhance the electrode kinetics of above mentioned electrochemical reactions. In this review article, first of all, the electronic and redox chemistry of phthalocyanine was discussed to understand the existed activity descriptors for H2, O2 and CO2 electrocatalysis. Then, we emphasized the potential candidature of MPcs as electrode materials in various energy conversion and storage devices along with their reaction mechanisms. Furthermore, several specific challenges related to activity and durability and future aspects with MPcs based materials are also discussed.