The　progressive　transfer　of　photogenerated　electrons　between　the　catalyst　components　and　reactants　is　of　great　significance　for　photocatalysis.　Amorphous　Pd　(PdA)　and　oxygen　vacancies　(VOs)　were　simultaneously　introduced　in　Pd-In2O3　exploiting　hydrogen-induced　amorphization　effects;　0.6　wt%　Pd-In2O3　exhibited　a　4.5-fold　increase　in　activity　and　a　3.2-fold　higher　selectivity　toward　CH3OH　+　CO　(63.62　%)　compared　with　In2O3.　Multiple　in　situ　techniques　and　theoretical　calculations　revealed　that　intercomponent　electron　transfer　channels　were　established　via　various　interface　structures　formed　between　PdA　or　crystalline　Pd　(PdC)　and　In2O3;　PdA　acted　as　electronic　pump,　facilitating　the　transfer　and　separation　of　photogenerated　electrons,　resulting　in　their　subsequent　enrichment　on　the　surface　of　PdA.　Simultaneously,　PdA　acted　as　electron-donating　adsorption　site　for　H2O,　increasing　the　number　of　electrons　received　by　H2O,　further　inhibiting　the　competitive　adsorption　of　H2O　and　CO2　on　VO　sites,　and　promoting　the　hydrogen　evolution　reaction.　Additionally,　the　electronic　coupling　between　PdC　and　VOs　could　significantly　decrease　the　electron-donating　ability　of　VOs,　reducing　the　number　of　electrons　received　by　CO2,　thus　effectively　regulating　the　degree　of　CO2　reduction.　This　study　employs　PdA/PdC　and　VOs　to　synergistic　optimize　the　progressive　transfer　of　photogenerated　electrons,　and　presents　a　novel　approach　for　elucidating　the　catalytic　mechanism.　©　2024　Elsevier　B.V.