The　confined　catalyst　can　disperse　and　stabilize　the　nanoparticles　through　spatial　confinement,　prevent　them　from　agglomeration,　and　improve　the　stability　of　the　catalyst.　The　confined　catalyst　can　also　subtly　change　the　electronic　structure　of　the　active　center　and　the　chemical　environment　near　the　active　center　through　chemical　coordination,　thus　improving　the　activity　of　the　catalyst.　However,　the　synthesis　of　ultrafine　NPs　and　the　scalable　production　of　the　resulting　catalysts　remain　challenging.　Here,　we　report　a　histidine　metal　(2+)　complexation　for　the　synthesis　of　highly　efficient　and　selective　MCM-41-carbon-confined　PtCo　nanoalloys.　Histidine　easily　chelates　metal　(2+)　electrostatically　interacting　with　cetyltrimethylammonium　bromide　(CTAB)　micelles,　which　enables　the　facile　and　scalable　synthesis　of　ultrafine　bimetallic　NPs　and　mesoporous　materials　in　one　step.　Characterization　shows　that　these　bimetallic　NPs,　for　instance　PtCo　nanoalloys,　are　confined　within　the　mesoporous　channels　of　the　MCM-41-C　material.　As　a　result,　the　MCM-41-C-confined　PtCo　(PtCo/MCM-41-C)　nanocatalyst　shows　excellent　catalytic　performances　in　the　selective　hydrogenation　of　biomass-derived　unsaturated　aldehydes　to　the　corresponding　unsaturated　alcohols　under　mild　conditions.　This　strategy　should　be　broadly　applicable　to　a　range　of　mesoporous　material-confined　metal-　and　metal　oxide　catalysts　for　heterogeneous　catalytic　reactions　toward　energy　and　environmental　applications.　©　2024　Elsevier　Ltd