Understanding the active species derived from metal− organic frameworks (MOFs) plays a vital role in the fabrication of highly efficient and stable oxygen evolution reaction (OER) electrocatalysts. Herein, a new alkaline-stable 3D nickel metal−organic framework (Ni-MOF), containing a 1D rod-packing chain structure fused with a tetranuclear nickel cluster [Ni 4 (μ 3 -OH) 2 ], is used as a target material to explore its OER properties. The electrocatalytic activities of pure Ni-MOF and hybrid materials made from Ni-MOF with different acetylene black loaded electrodes, such as glassy carbon, fluorine-doped tin oxide, and nickel foam, have been evaluated. Further analysis unravels that the enhanced OER performance might be attributed to the synergistic interactions of two catalytic active species between in situ formed β-Ni(OH) 2 and a tetranuclear Ni 4 (μ 3 -OH) 2 cluster in Ni-MOF. The findings will shed fresh light on the fabrication of MOF-derived catalysts for efficient electrochemical energy conversion.

Searching for non-noble metal catalysts with high activities and low price is critical to the commercialization of methanol oxidation in the process of fuel cells. Herein, two new pseudo-isomeric Ni metal-organic frameworks (Ni-MOFs) (CTGU-17/CTGU-18) have been prepared with 1,4-naphthalenedi-carboxylate (H 2 NDC), 4,4 0 -dipyridyl amine (DPA) and Ni(ClO 4 ) 2 under hydrothermal condition. Each phase contains one water molecule, but differs dramatically in its bonding to the framework, resulting in different topological networks with fourfold interpenetrating 4-connected dia net (CTGU-17) and (3,7)-connected net (CTGU-18) and diverse electrocatalytic performance for methanol oxidation reaction (MOR). Remarkably, by combining each MOF with the conductive additive, acetylene black (AB), a composite material, AB&CTGU-18(2:4) was confirmed to have an excellent performance for MOR with a high mass specific peak current of 442.3 mAÁmg -1 . The enhanced electrocatalytic activities and robustness might be attributed to the synergetic effect of acetylene black and the active metal centers of MOFs particles for methanol oxidation. The present work would provide a new insight for the rational design of MOFs-based composites with enhanced methanol oxidation reaction performance.

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