The nuclear quantum effects on the zero-point energy (ZPE), influencing adsorption of H₂and isotopologues on metal ions, are examined using normal mode analysis of ab initio electronic structure results for complexes with 17 metal cations. The lightest metallic nuclei, Li and Be, are found to be the most ‘quantum’. The largest selectivity in adsorption is predicted for Cu, Ni and Co ions. Analysis of the nuclear wavepacket dynamics on the ground state electronic potential energy surfaces (PES) performed for complexes of Li⁺and Cu⁺²with H₂/D₂/HD shows that the PES anharmonicity changes the ZPE by up to 9%.