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.