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[Display omitted] • The catalysts contain multi-active sites. • The micro twinning structure promotes catalytic activity towards different reactions. • The synergic effect exists and leads to the deviation from the Scaling Effect. The twinning structure could lead to unexpected effects on electrocatalytic performance; however, research on relevant mechanisms is still rare and there is still a lack of an effective and convenient strategy to introduce twinning structures into nanoparticles. In this work, inspired by the in-situ fcc-hcp phase transition in metals and benefiting from the features of Prussian blue analogues (PBAs), N-doped carbon cages-coated CoNi nanoparticles, which contain multi-active sites including alloyed nanoparticles, micro twinning structures and single atom sites could be effectively fabricated by pyrolyzing of CoNi-based PBAs. The catalyst exhibits an obvious enhancement in oxygen evolution/reduction reaction and hydrogen evolution reaction under alkaline conditions. Theoretical calculations verify that the micro-twinning structures originating from the fcc-hcp phase transition promote electrocatalytic activities significantly due to the optimized adsorption energy towards different intermediates. Moreover, the synergic effect between the multi-active sites may further optimize the electronic structures and lead to the deviation from the Scaling Effect. The water-splitting device and Zinc-Air battery are also assembled based on this micro- twinning electrocatalyst, which yields a maximum power density of 95 mW cm−2 and a low voltage of 1.76 V to reach 10 mA cm−2 current density, respectively. In all, this work contributes a simple and universal strategy to introduce both the multi-active sites and the twinning structure into transition metal-based catalysts, which improves the multi-catalytic activity towards different reactions significantly. [ABSTRACT FROM AUTHOR]

[Display omitted] • Based on a dual-confinement regulation, ternary metal-oxide activity sites derived from Co-MOFwere developed. • By chemical confinement, diverse sites were introduced; Then by spatial confinement , Cu x -O-Ni y -O-Co 3-x-y was obtained. • The Cu x -O-Ni y -O-Co 3-x-y modified glassy carbon electrode showed enhanced electrocatalytic activity for glucose oxidation. Based on a dual-confinement strategy on a cobalt-metal-organic framework (Co-MOF), a series of trimetallic-oxide catalysts of Cu x -O-Ni y -O-Co 3-x-y (x/y = 1/1, 1/3, 1/5 and 1/7) were developed for glucose oxidation. By chemical confinement regulation of ion exchange, diverse metal catalytic sites of Cu2+ and Ni2+ were introduced into Co-MOF, respectively; Then by spatial confinement synthesis of pyrolysis, trimetallic MOF of Cu x Ni y Co 3-x-y -MOF was transformed into trimetallic-oxide of Cu x -O-Ni y -O-Co 3-x-y , which maintained the regular morphology and highly ordered lattice structure of Co-MOF. The Cu x -O-Ni y -O-Co 3-x-y composite modified glassy carbon electrode (Cu x -O-Ni y -O-Co 3-x-y /GCE) exhibited enhanced electrocatalytic activity towards glucose oxidation when compared with Co-MOF/GCE, bimetallic MOFs of CuCo-MOF/GCE and NiCo-MOF/GCE, trimetallic MOF of Cu x Ni y Co 3-x-y -MOF/GCE, as well as monometallic oxide Co 3 O 4 /GCE and bimetallic oxides of CuCo 2 O 4 /GCE and NiCo 2 O 4 /GCE, which was mainly due to the synergistic catalysis of electrocatalytically active Co-O-Cu-O-Ni bridges. With Cu2+/Ni2+ molar ratio of 1/3, Cu x -O-Ni y -O-Co 3-x-y /GCE (x/y = 1/3) displayed excellent sensing behaviours on glucose detection. This work not only designed well-performed electrocatalysts for enhancing catalytic activity towards glucose oxidation, but also provided a new perspective to realize the controlled preparation of high-performance electrocatalysts. [ABSTRACT FROM AUTHOR]