Enhanced Catalytic Performance for Oxygen Reduction Reaction Derived from Nitrogen-Rich Tetrazolate-Based Heterometallic Metal–Organic Frameworks

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 channe...