Efficient non-noble metal catalysts for oxygen reduction reaction (ORR) have been highly attractive for the fabrication of cost-effective fuel cells. Metal–organic frameworks (MOFs) derived heteroatom-doped carbon-based (NC) electrocatalysts have exhibited comparable electrocatalytic activity for ORR as commercial Pt/C catalyst, which were highly dependent on their MOF precursor/template structures. In this particular work, two NC composites, NC-1100 and MnO@NC-1100 (NC, nitrogen-doped carbon), have been successfully synthesized, which were derived from novel nitrogen-rich tetrazolate-based metal–organic frameworks, [Cd2(L)­(OH)­(H2O)] (1) and [Cd3Mn­(L)2(OH)2(H2O)2] (2) (L, 5′-(4-(1H-tetrazol-5-yl)­(benzamido)­benzene-1,3-dioic acid), respectively. The structural differences between complexes 1 and 2 arose from the introduction of Mn­(II) to complex 2, where the Cd­(II) in 1 was partially replaced by Mn­(II). Both complexes 1 and 2 possessed three-dimensional (3D) structures with one-dimensional (1D) open channels. The resultant MnO@NC-1100 from the pyrolysis of complex 2 at 1100 °C under Ar atmosphere has indicated much better electrocatalystic behavior for ORR over the NC-1100 from complex 1, due to the existence of additional active sites of cubic phase MnO particles. The presence of initial Cd­(II) benefits the spatial isolation of Mn­(II) and prevents the sintering of MnO during the pyrolysis for MnO@NC-1100. The evaporation of Cd­(II) and the explosion of nitrogen-rich tetrazolate groups would also promote the surface area of the resulting catalysts. Our study further demonstrated that the multiple metal centers of MOF could be the rational strategy to enhance the electrocatalytical performance. Compared with NC-1100, MnO@NC-1100 exhibited the enhanced electrocatalytic activity with an onset potential (E onset ) of 0.90 V and a half-wave potential (E half‑wave ) of 0.74 V, which provided an insight view of the structure–property relationship.

Multifunctional metal-organic framework (MOF) materials have attracted great attentions due to their promising applications, water stability, however, has turned into a big challenge because of the existence of the weak coordination bonds. Two water stable Cd(II) MOFs, named [Cd 3 (L) 2 (H 2 O) 4 ] (1), [Cd 3 (L) 2 (bpy)(H 2 O) 3 ]•4H 2 O (2) (L = 5′-(4-(1H-tetrazol-5-yl)benzamido)benzene-1,3-dioic acid, bpy = 4,4′-bipyridine), were successfully prepared in this work, which have been compared with our previously reported [Cd 2 (L)(OH)(H 2 O)] (3) and [Cd 3 Mn(L) 2 (OH) 2 (H 2 O) 2 ] (4). Complexes 1, 3 and 4 exhibited 3D structures, while 2 displayed a 2D network. Complexes 1-4 have shown strong water stability due to the existence of the