Adjusting　the　structure　and　composition　of　active　sites　is　a　highly　effective　method　for　activating　linear　CO2　molecules.　Nonetheless,　precise　control　of　interfacial　chemistry　within　molecular-scale　environments　presents　a　significant　challenge　in　heterogeneous　catalysis.　In　our　study,　we　present　symmetry-broken　Mo-O-Co　triple-atom　active　sites　within　the　hybrid　zeolite　imidazole　framework　HZIF-CoMo.　These　sites　disrupt　the　electronic　balance　and　create　a　weak　built-in　electric　field,　thus　promoting　photocatalytic　CO2　reduction.　The　CO　yield　over　HZIF-CoMo　is　improved　to　3.1　mmol　g−1　h−1,　which　is　over　four　times　higher　than　the　parent　cobalt-imidazole　framework　MAF-6-Co.　Both　experimental　and　theoretical　studies　indicate　that　electronic　modulation　through　the　symmetry-breaking　Mo-O-Co　moiety　acts　as　an　organizing　knob　to　accelerate　charge　separation　and　result　in　more　carriers　participating　in　the　catalytic　reaction.　This　work　provides　important　insights　into　optimizing　site-related　electronic　structures　for　targeted　photocatalytic　reactions.　©　Science　China　Press　2025.