Sulfur was typically regarded as a poison to precious metal complex catalysts in hydroformylation of olefins.However,the combination of sulfur and phosphine may present an intriguing interaction with heterogeneous mon...Sulfur was typically regarded as a poison to precious metal complex catalysts in hydroformylation of olefins.However,the combination of sulfur and phosphine may present an intriguing interaction with heterogeneous mononuclear complex due to the difference of their electronegativities,and coordination capabilities.Herein,we report a novel sulfur-phosphine co-coordinated heterogeneous Rh mononuclear complex catalyst(Rh_(1)/POPs-PPh_(3)&S),which exhibits an unexpected 1.5–2.0 times catalytic activity for hydroformylation of olefins(C_(3)=,C_(5)=–C_(8)=),in comparison with the solely phosphine-coordinated Rh mononuclear complex catalyst(Rh_(1)/POPs-PPh_(3)).In contrast,sulfur coordination alone leads to severe sulfur poisoning with significantly inhibited catalytic performance.Experimental and theoretical analyses reveal that phosphine coordination promotes catalytic activity via its strong electron-donating ability,while sulfur occupies a coordination site and reduces the electronic density of Rh ions.The synergistical coordination of sulfur and phosphine optimizes the electronic density of active Rh ions and decreases the energy barrier of the rate-determining step of olefin insertion,thus enhancing the hydroformylation activity,regioselectivity and stability of Rh_(1)/POPs-PPh_(3)&S.展开更多
Organic electrode materials(OEMs)have attracted substantial attention for aqueous zinc-ion batteries(AZIBs)due to their advantages in relieving resource and environmental anxiety.However,the potential of OEMs is plagu...Organic electrode materials(OEMs)have attracted substantial attention for aqueous zinc-ion batteries(AZIBs)due to their advantages in relieving resource and environmental anxiety.However,the potential of OEMs is plagued by their low achievable capacity and high solubility.Here,we have proposed a new concept of“co-coordination force”and designed a rigid-flexible coupling crystalline polymer that can overcome the abovementioned limitations.The obtained crystalline polymer(BQSPNs)with multiredox centres makes the BQSPNs exist intermolecular hydrogen bonds(HB)among-C=O,-C=N,and-NH and consequently exhibits transverse two-dimensional arrays and longitudinalπ-πstacking structure.Additionally,in-situ FTIR,Raman,variable temperature FTIR spectra,and 2D nuclear overhauser effect spectroscopy(NOESY)well capture the existence and evolution process of HB during the electrochemistry reaction process of BQSPNs,uncovering the effect of HB in stabilizing the structure and promoting the reaction kinetics.As a result,the BQSPNs with rationally designed“co-coordination force”deliver a high capacity of 459.6 m Ah/g and a stable cycling lifetime for more than 100,000 cycles at 10 A/g in AZIBs.Our results disclose the HB effect and provide a brand-new strategy for high-performance OEMs design.展开更多
Lack of high-efficiency,cost-efficient,and well-stocked oxygen evolution reaction(OER)electrocatalysts is a main challenge in large-scale implementation of electrolytic water.By regulating the electronic structure of ...Lack of high-efficiency,cost-efficient,and well-stocked oxygen evolution reaction(OER)electrocatalysts is a main challenge in large-scale implementation of electrolytic water.By regulating the electronic structure of isolated single-atom metal sites,highperformance transition-metal-based catalysts can be fabricated to greatly improve the OER performance.Herein,we demonstrate single-atom manganese coordinated to nitrogen and sulfur species in two-dimensional graphene nanosheets MnNSG(NSG means N-and S-codoped graphene)as an active and durable OER catalyst with a low overpotential of 296 mV in alkaline media,compared to that of the benchmark IrO_(2) catalyst.Theoretical calculations and experimental measurements reveal that the Mn-N3S sites in the graphene matrix are the most active sites for the OER due to modified electronic structure of the Mn site by three nitrogen and one sulfur atoms coordination,which show lower theoretical overpotential than the Mn-N4 sites and over which the O–O formation step is the rate-determining step.展开更多
文摘Sulfur was typically regarded as a poison to precious metal complex catalysts in hydroformylation of olefins.However,the combination of sulfur and phosphine may present an intriguing interaction with heterogeneous mononuclear complex due to the difference of their electronegativities,and coordination capabilities.Herein,we report a novel sulfur-phosphine co-coordinated heterogeneous Rh mononuclear complex catalyst(Rh_(1)/POPs-PPh_(3)&S),which exhibits an unexpected 1.5–2.0 times catalytic activity for hydroformylation of olefins(C_(3)=,C_(5)=–C_(8)=),in comparison with the solely phosphine-coordinated Rh mononuclear complex catalyst(Rh_(1)/POPs-PPh_(3)).In contrast,sulfur coordination alone leads to severe sulfur poisoning with significantly inhibited catalytic performance.Experimental and theoretical analyses reveal that phosphine coordination promotes catalytic activity via its strong electron-donating ability,while sulfur occupies a coordination site and reduces the electronic density of Rh ions.The synergistical coordination of sulfur and phosphine optimizes the electronic density of active Rh ions and decreases the energy barrier of the rate-determining step of olefin insertion,thus enhancing the hydroformylation activity,regioselectivity and stability of Rh_(1)/POPs-PPh_(3)&S.
基金financially supported by the National Key R&D program of China(No.2022YFB2402200)National Natural Science Foundation of China(Nos.52271140,52171194)+2 种基金Youth Innovation Promotion Association CAS(No.2020230)Jilin Provincial NaturalFund(No.20230101205JC)National Natural Science Foundation of China Outstanding Youth Science Foundation of China(Overseas)。
文摘Organic electrode materials(OEMs)have attracted substantial attention for aqueous zinc-ion batteries(AZIBs)due to their advantages in relieving resource and environmental anxiety.However,the potential of OEMs is plagued by their low achievable capacity and high solubility.Here,we have proposed a new concept of“co-coordination force”and designed a rigid-flexible coupling crystalline polymer that can overcome the abovementioned limitations.The obtained crystalline polymer(BQSPNs)with multiredox centres makes the BQSPNs exist intermolecular hydrogen bonds(HB)among-C=O,-C=N,and-NH and consequently exhibits transverse two-dimensional arrays and longitudinalπ-πstacking structure.Additionally,in-situ FTIR,Raman,variable temperature FTIR spectra,and 2D nuclear overhauser effect spectroscopy(NOESY)well capture the existence and evolution process of HB during the electrochemistry reaction process of BQSPNs,uncovering the effect of HB in stabilizing the structure and promoting the reaction kinetics.As a result,the BQSPNs with rationally designed“co-coordination force”deliver a high capacity of 459.6 m Ah/g and a stable cycling lifetime for more than 100,000 cycles at 10 A/g in AZIBs.Our results disclose the HB effect and provide a brand-new strategy for high-performance OEMs design.
基金supported by the National Natural Science Foundation of China(Nos.22075099 and 31971322)the Education Department of Jilin Province(JJKH20220967KJ)+2 种基金the National Basic Research Program of China(Nos.2016YFA0203200 and 2020YFA0710702)CAS President’s International Fellowship Initiative(PIFI,2021PM0059)the State Key Laboratory of Natural and Biomimetic Drugs,Peking University.
文摘Lack of high-efficiency,cost-efficient,and well-stocked oxygen evolution reaction(OER)electrocatalysts is a main challenge in large-scale implementation of electrolytic water.By regulating the electronic structure of isolated single-atom metal sites,highperformance transition-metal-based catalysts can be fabricated to greatly improve the OER performance.Herein,we demonstrate single-atom manganese coordinated to nitrogen and sulfur species in two-dimensional graphene nanosheets MnNSG(NSG means N-and S-codoped graphene)as an active and durable OER catalyst with a low overpotential of 296 mV in alkaline media,compared to that of the benchmark IrO_(2) catalyst.Theoretical calculations and experimental measurements reveal that the Mn-N3S sites in the graphene matrix are the most active sites for the OER due to modified electronic structure of the Mn site by three nitrogen and one sulfur atoms coordination,which show lower theoretical overpotential than the Mn-N4 sites and over which the O–O formation step is the rate-determining step.
