The article explores the development of single-atom catalysts (SACs) for selective formic acid dehydrogenation. Through spin-polarized density functional theory (DFT) calculations, the study focuses on platinum-group SACs anchored on graphitic carbon nitride (g-C3N4). Results indicate that Pd and Au SACs demonstrate enhanced selectivity towards the dehydrogenation pathway, lowering the free energy barrier significantly compared to the competing dehydration route. Conversely, Rh SACs exhibit limited selectivity due to similar energy barriers for both reaction paths. The research emphasizes robust metal-support interactions influenced by d-p orbital hybridization, establishing a correlation between the d-band center position and catalytic selectivity. Furthermore, charge transfer effects on the electronic structure of SACs play a crucial role in modulating catalytic performance. These insights provide a foundational understanding for designing SACs and optimizing hydrogen production from formic acid, offering a pathway for more efficient and selective catalytic processes in the future.