Recent Advances in Nanoporous Organic Polymers (NPOPs) for Hydrogen Storage Applications

Nanoporous organic polymers (NPOPs) have emerged as versatile materials with robust thermal stability, large surface area (up to 2500 m2 g-1), and customizable porosity, making them ideal candidates for advanced hydrogen (H2) storage applications. This review provides a comprehensive analysis of various NPOPs, including covalent organic frameworks (COFs), hypercrosslinked polymers (HCLPs), conjugated microporous polymers (CMPs), and porous aromatic frameworks (POAFs). Notably, these materials demonstrate superior H2 storage capacities, achieving up to 10 wt% at cryogenic temperatures, which is essential for applying H2 as a clean energy carrier. The review also highlights recent advancements, such as integrating metal-organic frameworks (MOFs) into NPOPs, further enhancing storage capacities by up to 30%. Their multifaceted properties underpin various applications, from fuel storage and gas separation to water treatment and optical devices. This review explores the significance and versatility of NPOPs in H2 storage due to their unique properties and enhanced storage capacities. Additionally, recent advancements in utilizing NPOPs for H2 storage are highlighted with a detailed discussion of emerging trends and the synthesis of innovative NPOPs. The review concludes with a discussion of the advantages, applications, challenges, research, and future directions for research in this area.