Akademik Veri Yönetim Sistemi
Journal of Energy Storage, cilt.170, 2026 (SCI-Expanded, Scopus)
We present a first-principles screening of first-row transition-metal metalloporphyrin complexes as active-center models for hydrogen storage in porphyrinic metal–organic frameworks. Using wB97XD/def2-TZVP calculations, we optimize ScZn porphyrin complexes, quantify metal binding energies, and evaluate H2 adsorption for the first adsorption step, together with complex-level gravimetric hydrogen density and Van't Hoff-derived desorption/equilibrium temperatures. Electronic-structure analysis (frontier orbitals, conceptual-DFT descriptors, Mulliken charges, and PDOS/TDOS) is used to relate metal–N coordination, metal– H2 orbital hybridization, and charge redistribution to adsorption strength and reversibility. The results reveal a clear periodic trend. Sc-, Ti-, V-, and Cr-porphyrin complexes combine strongly exothermic metal incorporation with minimally distorted MN4 cores and accessible axial sites. For these metals, the first H2 adsorption energies range from values close to the commonly discussed moderate adsorption-energy window to somewhat stronger binding, while showing pronounced Kubas-type metal–H2 hybridization signatures and desorption temperatures compatible with near-ambient to moderately elevated operation at modest pressures. Fe retains recognizable Kubas character but less favorable thermodynamics due to stronger H2 binding, whereas Mn appears as a more borderline case for the first adsorption step in the present dataset. Co, Ni, Cu, and Zn display weak or less favorable adsorption together with limited electronic participation. Overall, the study identifies Ti- and V-based metalloporphyrin complexes, closely followed by Sc and Cr, as the most promising candidates within the present first-row series and proposes electronic and thermodynamic screening criteria that can be transferred to larger porphyrinic frameworks and future high-throughput discovery efforts.