Supramolecular cages and metal organic frameworks of porphyrins for a sustainable tomorrow: challenges and applications

For the exploration and development of secure, clean and renewable energy sources there is a dire need to search for alternative energy sources. Porphyrin having unique electronic properties and a linked outer coordinated framework is a versatile moiety for many energy related small molecule activation reactions. Owing to the pervasive role of porphyrins in natural systems, these molecules serve as attractive structures for engineering effective porous materials. Highly conjugated groups with large pi planes are expected to control the catalytic activity of metallated porphyrin systems. This perspective article outlines a brief overview of the synthetic pathways towards engineering of multifunctionalized porphyrins based on porous organic cages and their related metal organic frameworks (MOFs) which are considered excellent catalysts for carbon dioxide reduction and water splitting. The applicability of MOF based catalytic porphyrin systems is reviewed with respect to their ability for facilitating reduction of carbon dioxide, oxygen and hydrogen evolution along with future perspectives for the development of efficient porphyrin based electrocatalysts and photocatalysts for addressing the current energy demands.