In contrast to heterogeneous network frameworks(e.g.,covalent organic frameworks and metal‐organic frameworks)and porous organic polymers,porous organic cages(POCs)are soluble molecules in common organic solvents tha...In contrast to heterogeneous network frameworks(e.g.,covalent organic frameworks and metal‐organic frameworks)and porous organic polymers,porous organic cages(POCs)are soluble molecules in common organic solvents that provide significant potential for homogeneous catalysis.Herein,we report a triphenylphosphine‐derived quasi‐porous organic cage(denoted as POC‐DICP)as an efficient organic molecular cage ligand for Rh/PPh_(3) system‐catalyzed homogeneous hydroformylation reactions.POC‐DICP not only displays enhanced hydroformylation selectivity(aldehyde selectivity as high as 97%and a linear‐to‐branch ratio as high as 1.89)but can also be recovered and reused via a simple precipitation method in homogeneous reaction systems.We speculate that the reason for the high activity and good selectivity is the favorable geometry(cone angle=123.88°)and electronic effect(P site is relatively electron‐deficient)of POC‐DICP,which were also demonstrated by density functional theory calculations and X‐ray absorption fine‐structure characterization.展开更多
Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hinderin...Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hindering an in-depth understanding of the catalytic mechanism.In this work,uniform Pt-N_(1)O_(1)Cl_(4)sites chelated via C-N and C=O bonds along the one-dimensional and open channels of TP-TTA-COF were established.Different from conventional single-metal sites constructed for the near-free platinum for hydrogen evolution,the as-constructed PtCl-COF showed 2e−oxygen reduction for H_(2)O_(2)production.We tracked the dynamic evolution process of atomic Pt sites in which Pt-N_(1)O_(1)Cl_(4)was transformed into Pt-N_(1)O_(1)(OH)_(2)using in situ X-ray adsorption.The theoretical calculations revealed that the strong Pt-support interaction in Pt-N_(1)O_(1)(OH)_(2)facilitated*OOH formation and thus led to higher selectivity and activity for the oxygen reduction reaction in the 2e−pathway.This work can expand the applications of COFs through the regulation of their local electronic states for the manipulation of the metal center.展开更多
文摘In contrast to heterogeneous network frameworks(e.g.,covalent organic frameworks and metal‐organic frameworks)and porous organic polymers,porous organic cages(POCs)are soluble molecules in common organic solvents that provide significant potential for homogeneous catalysis.Herein,we report a triphenylphosphine‐derived quasi‐porous organic cage(denoted as POC‐DICP)as an efficient organic molecular cage ligand for Rh/PPh_(3) system‐catalyzed homogeneous hydroformylation reactions.POC‐DICP not only displays enhanced hydroformylation selectivity(aldehyde selectivity as high as 97%and a linear‐to‐branch ratio as high as 1.89)but can also be recovered and reused via a simple precipitation method in homogeneous reaction systems.We speculate that the reason for the high activity and good selectivity is the favorable geometry(cone angle=123.88°)and electronic effect(P site is relatively electron‐deficient)of POC‐DICP,which were also demonstrated by density functional theory calculations and X‐ray absorption fine‐structure characterization.
基金Natural Science Foundation of Shanghai,Grant/Award Number:20ZR1464000CAS Project for Young Scientists in Basic Research,Grant/Award Number:YSBR-022。
文摘Covalent organic frameworks(COFs)have been well developed in electrocatalytic systems owing to their controllable skeletons,porosities,and functions.However,the catalytic process in COFs remains underexplored,hindering an in-depth understanding of the catalytic mechanism.In this work,uniform Pt-N_(1)O_(1)Cl_(4)sites chelated via C-N and C=O bonds along the one-dimensional and open channels of TP-TTA-COF were established.Different from conventional single-metal sites constructed for the near-free platinum for hydrogen evolution,the as-constructed PtCl-COF showed 2e−oxygen reduction for H_(2)O_(2)production.We tracked the dynamic evolution process of atomic Pt sites in which Pt-N_(1)O_(1)Cl_(4)was transformed into Pt-N_(1)O_(1)(OH)_(2)using in situ X-ray adsorption.The theoretical calculations revealed that the strong Pt-support interaction in Pt-N_(1)O_(1)(OH)_(2)facilitated*OOH formation and thus led to higher selectivity and activity for the oxygen reduction reaction in the 2e−pathway.This work can expand the applications of COFs through the regulation of their local electronic states for the manipulation of the metal center.
