It is significant to optimize geometric configuration of metal catalytic sites and boost their catalytic activity. Herein, we synthesized isolated single Zn-N₄ sites on N-doped carbon (Zn-CN) by pyrolyzing zeolite imidazole framework-8 (ZIF-8) at different temperatures. For the reciprocal transformation between benzyl alcohol and benzaldehyde, the catalytic activities of Zn-CN catalysts exhibited a volcano-like trend as the pyrolysis temperatures increased. The optimal catalyst was Zn-CN-900, with outstanding catalytic activity exceeding commercial 20 wt.% Pd/C and 20 wt.% Pt/C, promising to substitute the noble metal-based catalysts. X-ray absorption near-edge structure (XANES) measurements and density functional theory (DFT) calculation revealed the gradual transformation from tetrahedral ZnN₄ sites of ZIF-8 into planar ZnN₄ sites above 700 °C, with the maximum planar ZnN₄ sites in Zn-CN-900. The stronger adsorption between reactants and planar ZnN₄ sites facilitated the activation of reactants compared with tetrahedral ZnN₄ sites. This work will provide valuable insight into rational design of efficient catalysts by optimizing geometric configuration of catalytic sites.