Formic acid oxidation is an important electrocatalytic reaction in proton- exchange membrane （PEM） fuel cells, in which both active sites and species adsorption/activation play key roles. In this study, we have deve...Formic acid oxidation is an important electrocatalytic reaction in proton- exchange membrane （PEM） fuel cells, in which both active sites and species adsorption/activation play key roles. In this study, we have developed hollow Pd-Ag alloy nanostructures with high active surface areas for application to electrocatalytic formic acid oxidation. When a certain amount of Ag is incorporated into a Pd lattice, which is already a highly active material for formic acid oxidation, the electrocatalytic activity can be significantly boosted. As indicated by theoretical simulations, coupling between Pd and Ag induces polarization charges on Pd catalytic sites, which can enhance the adsorption of HCO0＊ species. As a result, the designed electrocatalysts can achieve reduced Pd usage and enhanced catalytic properties at the same time. This study represents an approach that simultaneously fabricates hollow structures to increase the number of active sites and utilizes interatomic interactions to tune species adsorption/ activation towards improved electrocatalytic performance.展开更多
Engineering the internal structure and chemical composition of nanomaterials in a cost-effective way has been challenging, especially for enhancing their performance for a given application. Herein, we report a genera...Engineering the internal structure and chemical composition of nanomaterials in a cost-effective way has been challenging, especially for enhancing their performance for a given application. Herein, we report a general strategy to fabricate hollow nanostructures of ruthenium-based binary or ternary oxides via a galvanic replacement process together with a subsequent thermal treatment. In particular,the as-prepared NiO-RuO_2 hollow nanostructures loaded on carbon nanotubes(hNiO-RuO_2/CNT) with RuO_2 mass ratio at 19.6% for a supercapacitor adopting the KOH electrolyte exhibit high specific capacitances of 740 F g^(-1) at a constant current density of 1 A g^(-1) with good cycle stability. The specific capacitance for hNiO-RuO_2/CNT electrodes maintains638.4 F g^(-1) at a current density of 5 A g^(-1). This simple approach may shed some light on the way for making a wide range of metal oxides with tunable nanostructures and compositions for a variety of applications.展开更多
文摘Formic acid oxidation is an important electrocatalytic reaction in proton- exchange membrane （PEM） fuel cells, in which both active sites and species adsorption/activation play key roles. In this study, we have developed hollow Pd-Ag alloy nanostructures with high active surface areas for application to electrocatalytic formic acid oxidation. When a certain amount of Ag is incorporated into a Pd lattice, which is already a highly active material for formic acid oxidation, the electrocatalytic activity can be significantly boosted. As indicated by theoretical simulations, coupling between Pd and Ag induces polarization charges on Pd catalytic sites, which can enhance the adsorption of HCO0＊ species. As a result, the designed electrocatalysts can achieve reduced Pd usage and enhanced catalytic properties at the same time. This study represents an approach that simultaneously fabricates hollow structures to increase the number of active sites and utilizes interatomic interactions to tune species adsorption/ activation towards improved electrocatalytic performance.
基金supported by the National Natural Science Foundation of China(2117322621376247+4 种基金21573240and 21506225)Center for MesoscienceInstitute of Process EngineeringChinese Academy of Sciences(COM2015A001)the Knowledge Innovation Program of the Chinese Academy of Sciences(KGCX2-YW-341)
文摘Engineering the internal structure and chemical composition of nanomaterials in a cost-effective way has been challenging, especially for enhancing their performance for a given application. Herein, we report a general strategy to fabricate hollow nanostructures of ruthenium-based binary or ternary oxides via a galvanic replacement process together with a subsequent thermal treatment. In particular,the as-prepared NiO-RuO_2 hollow nanostructures loaded on carbon nanotubes(hNiO-RuO_2/CNT) with RuO_2 mass ratio at 19.6% for a supercapacitor adopting the KOH electrolyte exhibit high specific capacitances of 740 F g^(-1) at a constant current density of 1 A g^(-1) with good cycle stability. The specific capacitance for hNiO-RuO_2/CNT electrodes maintains638.4 F g^(-1) at a current density of 5 A g^(-1). This simple approach may shed some light on the way for making a wide range of metal oxides with tunable nanostructures and compositions for a variety of applications.
基金supported by the National Natural Science Foundation of China (21601137)the Natural Science Foundation of Zhejiang Province (LQ16B010003)the Basic Science and Technology Research Project of Wenzhou, Zhejiang Province (G20190007)。
