Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence states.However,the development of bimetallic ...Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence states.However,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory stage.Here,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated backbone.The supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first time.The as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V vs.reversible hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR process.Thus,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.展开更多
Phenylethynyl palladium(Ⅱ) complexes have proven to be effective catalysts for coordination polymerization of isocyanides. In this work, two new phenylethynyl palladium(Ⅱ) initiators bearing bromide(1b) and iodide(1...Phenylethynyl palladium(Ⅱ) complexes have proven to be effective catalysts for coordination polymerization of isocyanides. In this work, two new phenylethynyl palladium(Ⅱ) initiators bearing bromide(1b) and iodide(1c) were synthesized and applied for living polymerization of aryl and alkyl isocyanides. The coordinated halogen anions can significantly influence the kinetics of polymerization, with the observed order of reaction rates being 1c(Ⅰ)>1 b(Br)>1a(Cl). Impressively, 1c not only accelerates the reaction rate in both the initiation stage and propagation stage, but also can polymerize less active monomers that cannot be reacted by 1a. DFT calculations were then employed to understand the detailed mechanism and the halogen effects in this insertion polymerization process.展开更多
基金the National Natural Science Foundation of China(No.22275139)Natural Science Foundation of Tianjin(No.22JCZDJC00510).
文摘Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence states.However,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory stage.Here,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated backbone.The supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first time.The as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V vs.reversible hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR process.Thus,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.
基金supported by the National Natural Science Foundation of China (21771049, 21622402)the Fundamental Research Funds for the Central Universities+2 种基金the National Thousand Young Talents Programthe Jiangsu Specially-Appointed Professor Planthe Natural Science Foundation of Jiangsu Province (BK20170631)
文摘Phenylethynyl palladium(Ⅱ) complexes have proven to be effective catalysts for coordination polymerization of isocyanides. In this work, two new phenylethynyl palladium(Ⅱ) initiators bearing bromide(1b) and iodide(1c) were synthesized and applied for living polymerization of aryl and alkyl isocyanides. The coordinated halogen anions can significantly influence the kinetics of polymerization, with the observed order of reaction rates being 1c(Ⅰ)>1 b(Br)>1a(Cl). Impressively, 1c not only accelerates the reaction rate in both the initiation stage and propagation stage, but also can polymerize less active monomers that cannot be reacted by 1a. DFT calculations were then employed to understand the detailed mechanism and the halogen effects in this insertion polymerization process.
