Alloying Pt with transition metals can significantly improve the catalytic properties for the oxygen reduction reaction(ORR).However,the application of Pt-transition metal alloys in fuel cells is largely limited by po...Alloying Pt with transition metals can significantly improve the catalytic properties for the oxygen reduction reaction(ORR).However,the application of Pt-transition metal alloys in fuel cells is largely limited by poor long-term durability because transition metals can easily leach.In this study,we developed a nonmetallic doping approach and prepared a P-doped Pt catalyst with excellent durability for the ORR.Carbon-supported core-shell nanoparticles with a P-doped Pt core and Pt shell(denoted as PtPx@Pt/C)were synthesized via heat-treatment phosphorization of commercial Pt/C,followed by acid etching.Compositional analysis using electron energy loss spectroscopy and X-ray photoelectron spectroscopy clearly demonstrated that Pt was enriched in the near-surface region(approximately 1 nm)of the carbon-supported core-shell nanoparticles.Owning to P doping,the ORR specific activity and mass activity of the PtP_(1.4)@Pt/C catalyst were as high as 0.62 mA cm^(–2)and 0.31 mAμgPt–^(1),respectively,at 0.90 V,and they were enhanced by 2.8 and 2.1 times,respectively,in comparison with the Pt/C catalyst.More importantly,PtP_(1.4)@Pt/C exhibited superior stability with negligible mass activity loss(6%after 30000 potential cycles and 25%after 90000 potential cycles),while Pt/C lost 46%mass activity after 30000 potential cycles.The high ORR activity and durability were mainly attributed to the core-shell nanostructure,the electronic structure effect,and the resistance of Pt nanoparticles against aggregation,which originated from the enhanced ability of the PtP_(1.4)@Pt to anchor to the carbon support.This study provides a new approach for constructing nonmetal-doped Pt-based catalysts with excellent activity and durability for the ORR.展开更多
A nonmetal doping strategy was exploited for the conventional La_(0.5)Sr_(0.5)FeO_(3-δ)(LSF)cathode,allowing high performance for proton-conducting solid oxide fuel cells(H-SOFCs).Unlike previous studies focusing on ...A nonmetal doping strategy was exploited for the conventional La_(0.5)Sr_(0.5)FeO_(3-δ)(LSF)cathode,allowing high performance for proton-conducting solid oxide fuel cells(H-SOFCs).Unlike previous studies focusing on the utilization of metal oxides as dopants,phosphorus,which is a nonmetal element,was used as the cation dopant for LSF by partially replacing Fe ions to form the new La_(0.5)Sr_(0.5)Fe_(0.9)P_(0.1)O_(3-δ)(LSFP)compound.The H-SOFC using the LSFP cathode showed a two-fold peak power density as compared to that using the LSF cathode.Both experimental studies and first-principle calculations were used to unveil the mechanisms for the high performance of the LSFP cells.展开更多
文摘Alloying Pt with transition metals can significantly improve the catalytic properties for the oxygen reduction reaction(ORR).However,the application of Pt-transition metal alloys in fuel cells is largely limited by poor long-term durability because transition metals can easily leach.In this study,we developed a nonmetallic doping approach and prepared a P-doped Pt catalyst with excellent durability for the ORR.Carbon-supported core-shell nanoparticles with a P-doped Pt core and Pt shell(denoted as PtPx@Pt/C)were synthesized via heat-treatment phosphorization of commercial Pt/C,followed by acid etching.Compositional analysis using electron energy loss spectroscopy and X-ray photoelectron spectroscopy clearly demonstrated that Pt was enriched in the near-surface region(approximately 1 nm)of the carbon-supported core-shell nanoparticles.Owning to P doping,the ORR specific activity and mass activity of the PtP_(1.4)@Pt/C catalyst were as high as 0.62 mA cm^(–2)and 0.31 mAμgPt–^(1),respectively,at 0.90 V,and they were enhanced by 2.8 and 2.1 times,respectively,in comparison with the Pt/C catalyst.More importantly,PtP_(1.4)@Pt/C exhibited superior stability with negligible mass activity loss(6%after 30000 potential cycles and 25%after 90000 potential cycles),while Pt/C lost 46%mass activity after 30000 potential cycles.The high ORR activity and durability were mainly attributed to the core-shell nanostructure,the electronic structure effect,and the resistance of Pt nanoparticles against aggregation,which originated from the enhanced ability of the PtP_(1.4)@Pt to anchor to the carbon support.This study provides a new approach for constructing nonmetal-doped Pt-based catalysts with excellent activity and durability for the ORR.
基金the National Natural Science Foundation of China,Grant/Award Number:51972183the Hundred Youth Talents Program of Hunanthe Startup Funding for Talents at University of South China。
文摘A nonmetal doping strategy was exploited for the conventional La_(0.5)Sr_(0.5)FeO_(3-δ)(LSF)cathode,allowing high performance for proton-conducting solid oxide fuel cells(H-SOFCs).Unlike previous studies focusing on the utilization of metal oxides as dopants,phosphorus,which is a nonmetal element,was used as the cation dopant for LSF by partially replacing Fe ions to form the new La_(0.5)Sr_(0.5)Fe_(0.9)P_(0.1)O_(3-δ)(LSFP)compound.The H-SOFC using the LSFP cathode showed a two-fold peak power density as compared to that using the LSF cathode.Both experimental studies and first-principle calculations were used to unveil the mechanisms for the high performance of the LSFP cells.
