On the way towards a sustainable low-carbon future, the design and construction of chemical or physical adsorbents for CO₂ capture and clean energy storage are vital technology. The incorporation of accessible nitrogen-donor sites into the pore walls of porous adsorbents can dramatically affect the CO₂ uptake capacity and selectivity on account of the dipole-quadrupole interactions between the polarizable CO₂ molecule and the accessible nitrogen site. In the present work, a nitrogen-rich rth-type metal-organic framework (MOF) was constructed based on rational design and careful synthesis. The MOF presents exceptionally high uptake capacity not only for CO₂ but also for H₂, which is attributed to favorable interactions between the gas molecules and the nitrogen-rich triazole units of the MOF proved by both experimental measurements and theoretical molecular simulations.