Although　the　highly　porous　crystalline　metal-organic　frameworks　(MOFs)　are　promising　candidates　as　active　electrocatalysts　for　CO2　reduction　reaction　(CO2RR),　their　poor　electronic　conductivities　severely　limit　their　applications.　Viologens　(Vg)　and　their　derivatives　are　able　to　act　as　electron-transfer　mediators　(ETMs)　to　facilitate　rapid　electron　transfer　to　active　sites　but　have　not　yet　been　integrated　into　MOFs　for　the　CO2RR.　Herein,　viologen　groups　are　integrated　into　cobalt　porphyrin　(Por(Co))-based　MOFs　for　the　first　time　to　act　as　ETMs　to　enhance　the　electron-transfer　capacity　and　thus　improve　the　activity　of　the　CO2RR.　The　obtained　optimal　Vg-Por(Co)-MOF(9　:　1)　(Por(Co)　:　Vg　=　9　:　1)　showed　excellent　catalytic　performance　with　a　high　faradaic　efficiency　of　CO　(FECO　=　93.8%,　2.3　V)　and　large　CO　partial　current　density　of　(jCO)　111.1　mA　cm−2　at　2.9　V　in　the　CO2RR　in　a　membrane　electrode　assembly　(MEA)　system.　The　FECO　and　jCO　values　for　Vg-Por(Co)-MOF(9　:　1)　are　about　1.9　and　2　times　larger　than　those　of　Por(Co)-MOF　containing　free　Vg　as　the　ETM　(49.2%　and　51.4　mA　cm−2,　respectively).　Such　excellent　performance　of　Vg-Por(Co)-MOF(9　:　1)　also　surpasses　that　of　the　majority　of　other　cobalt-based　electrocatalysts,　which　make　it　stand　out　as　being　among　the　benchmark　electrocatalysts　for　CO2　to　CO　generation.　This　work　offers　an　efficient　method　for　designing　extremely　effective　porous　frameworks　for　enhanced　electrocatalysis　through　increasing　electrical　conductivity.　©　2023　The　Royal　Society　of　Chemistry.