Formic acid is highlighted as an efficient hydrogen storage material due to its lower cost, lower toxicity, and faster hydrogenation kinetics compared to other organic liquid hydrogen storage options. The article discusses the synthesis of layered double hydroxide catalysts grafted with different amine groups for formic acid dehydrogenation. It emphasizes the importance of primary amine functionalities in synthesizing ultrafine Pd nanoparticles, with initial turnover frequencies of 1250 h−1 at room temperature. The study also includes density functional theory calculations demonstrating the effectiveness of controlling Pd sites at 2 nm for optimal formic acid dehydrogenation by promoting hydrogen formation and avoiding dehydration reactions. The subsequent hydrogenation of CO2 into formic acid/formate on Pd-based catalysts achieves high turnover frequencies, showcasing the potential for efficient H2 interconversion cycles. The research underscores the significance of formic acid as a renewable resource and its potential for sustainable hydrogen generation and CO2 utilization. Through insights into catalyst design and nanoparticle size effects, the study provides valuable contributions to the fields of renewable energy, catalysis, and sustainable chemistry.