Recently,metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications.The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic clus...Recently,metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications.The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic cluster-based organic frameworks are investigated using density functional theory.Firstly,the catalytic activities of heterometallic clusters are investigated.Among all heterometallic clusters,Fe_(2)Mn–Mn has a minimum overpotential of 0.35 V for oxygen reduction reaction,and Fe_(2)Co–Co possesses the smallest overpotential of 0.32 V for oxygen evolution reaction,respectively 100 and 50 mV lower than those of Pt(111)and RuO_(2)(110)catalysts.The analysis of the potential gap of Fe_(2)M clusters indicates that Fe_(2)Mn,Fe_(2)Co,and Fe_(2)Ni clusters possess good bifunctional catalytic activity.Additionally,the catalytic activity of Fe_(2)Mn and Fe_(2)Co connected through 3,3′,5,5′-azobenzenetetracarboxylate linker to form Fe_(2)M–PCN–Fe_(2)M is explored.Compared with Fe_(2)Mn–PCN–Fe_(2)Mn,Fe_(2)Co–PCN–Fe_(2)Co,and isolated Fe_(2)M clusters,the mixed-metal Fe_(2)Co–PCN–Fe_(2)Mn possesses excellent bifunctional catalytic activity,and the values of potential gap on the Mn and Co sites of Fe_(2)Co–PCN–Fe_(2)Mn are 0.69 and 0.70 V,respectively.Furthermore,the analysis of the electron structure indicates that constructing a mixed-metal cluster can efficiently enhance the electronic properties of the catalyst.In conclusion,the mixed-metal cluster strategy provides a new approach to further design and synthesize high-efficiency bifunctional electrocatalysts.展开更多
Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the mass...Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the massive precious metal usage in current membrane electrode assembly （MEA） technology greatly inhibits their actual applications. Here we demonstrate a new type of anode constructed by confining highly active nanoengineered catalysts into an ultra-thin catalyst layer with thickness around 100 nm. Specifically, an atomic layer of platinum is first deposited onto nanoporous gold （NPG） leaf to achieve high utilization of Pt and easy accessibility of both reactants and electrons to active sites. These NPG-Pt core/shell nanostructures are further decorated by a sub-monolayer of Bi to create highly active reaction sites for formic acid electro-oxidation. Thus obtained layer-structured NPG-Pt-Bi thin films allow a dramatic decrease in Pt usage down to 3 ~tg.cm-2, while maintaining very high electrode activity and power performance at sufficiently low overall precious metal loading. Moreover, these electrode materials show superior durability during half-year test in actual DFAFCs, with remarkable resistance to common impurities in formic acid, which together imply their great potential in applications in actual devices.展开更多
基金supported by the Science and Technology Project of Sichuan Province(Grant No.2022YFS0447)the Local Science and Technology Development Fund Projects Guided by the Central Government of China(Grant No.2021ZYD0060)+2 种基金the Science and Technology Project of Southwest Petroleum University(Grant No.2021JBGS03)the Special Project of Science and Technology Strategic Cooperation between Nanchong City and Southwest Petroleum University(Grant No.SXQHJH064)the Postgraduate Research and Innovation Fund of Southwest Petroleum University(Grant No.2021CXYB14).
文摘Recently,metal–organic frameworks are one of the potential catalytic materials for electrocatalytic applications.The oxygen reduction reaction and oxygen evolution reaction catalytic activities of heterometallic cluster-based organic frameworks are investigated using density functional theory.Firstly,the catalytic activities of heterometallic clusters are investigated.Among all heterometallic clusters,Fe_(2)Mn–Mn has a minimum overpotential of 0.35 V for oxygen reduction reaction,and Fe_(2)Co–Co possesses the smallest overpotential of 0.32 V for oxygen evolution reaction,respectively 100 and 50 mV lower than those of Pt(111)and RuO_(2)(110)catalysts.The analysis of the potential gap of Fe_(2)M clusters indicates that Fe_(2)Mn,Fe_(2)Co,and Fe_(2)Ni clusters possess good bifunctional catalytic activity.Additionally,the catalytic activity of Fe_(2)Mn and Fe_(2)Co connected through 3,3′,5,5′-azobenzenetetracarboxylate linker to form Fe_(2)M–PCN–Fe_(2)M is explored.Compared with Fe_(2)Mn–PCN–Fe_(2)Mn,Fe_(2)Co–PCN–Fe_(2)Co,and isolated Fe_(2)M clusters,the mixed-metal Fe_(2)Co–PCN–Fe_(2)Mn possesses excellent bifunctional catalytic activity,and the values of potential gap on the Mn and Co sites of Fe_(2)Co–PCN–Fe_(2)Mn are 0.69 and 0.70 V,respectively.Furthermore,the analysis of the electron structure indicates that constructing a mixed-metal cluster can efficiently enhance the electronic properties of the catalyst.In conclusion,the mixed-metal cluster strategy provides a new approach to further design and synthesize high-efficiency bifunctional electrocatalysts.
文摘Direct formic acid fuel cells （DFAFCs） allow highly efficient low temperature conversion of chemical energy into electricity and are expected to play a vital role in our future sustainable society. However, the massive precious metal usage in current membrane electrode assembly （MEA） technology greatly inhibits their actual applications. Here we demonstrate a new type of anode constructed by confining highly active nanoengineered catalysts into an ultra-thin catalyst layer with thickness around 100 nm. Specifically, an atomic layer of platinum is first deposited onto nanoporous gold （NPG） leaf to achieve high utilization of Pt and easy accessibility of both reactants and electrons to active sites. These NPG-Pt core/shell nanostructures are further decorated by a sub-monolayer of Bi to create highly active reaction sites for formic acid electro-oxidation. Thus obtained layer-structured NPG-Pt-Bi thin films allow a dramatic decrease in Pt usage down to 3 ~tg.cm-2, while maintaining very high electrode activity and power performance at sufficiently low overall precious metal loading. Moreover, these electrode materials show superior durability during half-year test in actual DFAFCs, with remarkable resistance to common impurities in formic acid, which together imply their great potential in applications in actual devices.
