Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their m...Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel cells.Herein,we report a new class of hierarchically skeletal Pt-Ni nanocrystals(HSNs)with a multi-layered structure,prepared by an inorganic acid-induced solvothermal method.The addition of H_(2)SO_(4)to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired structure.The Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V(versus the reversible hydrogen electrode)towards ORR in 0.1-M HClO_(4),which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid;it is additionally 8.9-fold higher than that of the commercial Pt/C catalyst.Meanwhile,it displays enhanced stability,with only 21.6%mass activity loss after 10,000 cycles(0.6–1.0 V)for ORR.Furthermore,the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for MOR.The superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity,induced by strain effects,provided by the unique hierarchically skeletal alloy structure.The novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.展开更多
以六水合硝酸钴(Co(NO_3)_2·6H_2O)为钴源,硫脲(CS(NH_2)_2)为硫源,采用溶剂热法和低温固相硫化的方法制备出了介孔Co_3S_4纳米棒。采用X射线衍射(XRD),扫描电镜(SEM)和透射电镜(TEM)等手段对于介孔Co_3S_4纳米棒进行表征,同时对介...以六水合硝酸钴(Co(NO_3)_2·6H_2O)为钴源,硫脲(CS(NH_2)_2)为硫源,采用溶剂热法和低温固相硫化的方法制备出了介孔Co_3S_4纳米棒。采用X射线衍射(XRD),扫描电镜(SEM)和透射电镜(TEM)等手段对于介孔Co_3S_4纳米棒进行表征,同时对介孔Co_3S_4纳米棒进行了电催化产氧性能测试。结果表明:介孔Co_3S_4纳米棒的起始过电位为0.37 V,塔菲尔斜率为76.95 m V/dec,具有高的电催化产氧性能。展开更多
文摘Pt based materials are the most efficient electrocatalysts for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR)in fuel cells.Maximizing the utilization of Pt based materials by modulating their morphologies to expose more active sites is a fundamental objective for the practical application of fuel cells.Herein,we report a new class of hierarchically skeletal Pt-Ni nanocrystals(HSNs)with a multi-layered structure,prepared by an inorganic acid-induced solvothermal method.The addition of H_(2)SO_(4)to the synthetic protocol provides a critical trigger for the successful growth of Pt-Ni nanocrystals with the desired structure.The Pt-Ni HSNs synthesized by this method exhibit enhanced mass activity of 1.25 A mgpt−1 at 0.9 V(versus the reversible hydrogen electrode)towards ORR in 0.1-M HClO_(4),which is superior to that of Pt-Ni multi-branched nanocrystals obtained by the same method in the absence of inorganic acid;it is additionally 8.9-fold higher than that of the commercial Pt/C catalyst.Meanwhile,it displays enhanced stability,with only 21.6%mass activity loss after 10,000 cycles(0.6–1.0 V)for ORR.Furthermore,the Pt-Ni HSNs show enhanced activity and anti-toxic ability in CO for MOR.The superb activity of the Pt-Ni HSNs for ORR and MOR is fully attributed to an extensively exposed electrochemical surface area and high intrinsic activity,induced by strain effects,provided by the unique hierarchically skeletal alloy structure.The novel open and hierarchical structure of Pt-Ni alloy provides a promising approach for significant improvements of the activity of Pt based alloy electrocatalysts.
文摘以六水合硝酸钴(Co(NO_3)_2·6H_2O)为钴源,硫脲(CS(NH_2)_2)为硫源,采用溶剂热法和低温固相硫化的方法制备出了介孔Co_3S_4纳米棒。采用X射线衍射(XRD),扫描电镜(SEM)和透射电镜(TEM)等手段对于介孔Co_3S_4纳米棒进行表征,同时对介孔Co_3S_4纳米棒进行了电催化产氧性能测试。结果表明:介孔Co_3S_4纳米棒的起始过电位为0.37 V,塔菲尔斜率为76.95 m V/dec,具有高的电催化产氧性能。
