The long-range periodically ordered atomic structures in intermetallic nanoparticles(INPs)can significantly enhance both the electrocatalytic activity and electrochemical stability toward the oxygen reduction reaction...The long-range periodically ordered atomic structures in intermetallic nanoparticles(INPs)can significantly enhance both the electrocatalytic activity and electrochemical stability toward the oxygen reduction reaction(ORR)compared to the disordered atomic structures in ordinary solid-solution alloy NPs.Accordingly,through a facile and scalable synthetic method,a series of carbon-supported ultrafine Pt_3Co_(x)Mn_(1-x)ternary INPs are prepared in this work,which possess the"skin-like"ultrathin Pt shells,the ordered L1_(2) atomic structure,and the high-even dispersion on supports(L1_(2)-Pt_3Co_(x)Mn_(1-x)/~SPt INPs/C).Electrochemical results present that the composition-optimized L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C exhibits the highest electrocata lytic activity among the series,which are also much better than those of the pristine ultrafine Pt/C.Besides,it also has a greatly enhanced electrochemical stability.In addition,the effects of annealing temperature and time are further investigated.More importantly,such superior ORR electrocatalytic performance of L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C are also well demonstrated in practical fuel cells.Physicochemical characterization analyses further reveal the major origins of the greatly enhanced ORR electrocata lytic performance:the Pt-Co-Mn alloy-induced geometric and ligand effects as well as the extremely high L1_(2) atomic-ordering degree.This work not only successfully develops a highly active and stable ordered ternary intermetallic ORR electrocatalyst,but also elucidates the corresponding"structure-function"relationship,which can be further applied in designing other intermetallic(electro)catalysts.展开更多
Potentilla anserina L.(PA)belongs to the Rosaceae family,is a common edible plant in the Qinghai-Tibet Plateau areas of China.This study elucidates the mechanism upon which crude polysaccharide of PA(PAP)on fat accumu...Potentilla anserina L.(PA)belongs to the Rosaceae family,is a common edible plant in the Qinghai-Tibet Plateau areas of China.This study elucidates the mechanism upon which crude polysaccharide of PA(PAP)on fat accumulation in HepG2 cells stimulated by oleic acid(OA)and high fat high sugar induced mice.The result revealed that PAP inhibited lipid accumulation in obese mice and ameliorated the degree of damage in OA-induced HepG2 cells.Specifically,compared to the control group,the TG and TC levels were decreased in cells and mice serum,the aspartate transaminase and alamine aminotransferase contents were declined in liver of obese mice by PAP treatment.The expressions of adipogenic genes of SREBP-1c,C/EBPα,PPARγ,and FAS were inhibited after PAP treatment.Moreover,PAP increased the mRNA levels of CPT-1 and PPARα,which were involved in fatty acid oxidation.The present results indicated the PAP could alleviate the damage of liver associated with obesity and PAP treatment might provide a dietary therapeutic option for the treatment of hyperlipidemia.展开更多
基金supported by the National Key Research and Development Program of China(2021YFB4001301)the Science and Technology Commission of Shanghai Municipality(21DZ1208600)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2021ZD105)。
文摘The long-range periodically ordered atomic structures in intermetallic nanoparticles(INPs)can significantly enhance both the electrocatalytic activity and electrochemical stability toward the oxygen reduction reaction(ORR)compared to the disordered atomic structures in ordinary solid-solution alloy NPs.Accordingly,through a facile and scalable synthetic method,a series of carbon-supported ultrafine Pt_3Co_(x)Mn_(1-x)ternary INPs are prepared in this work,which possess the"skin-like"ultrathin Pt shells,the ordered L1_(2) atomic structure,and the high-even dispersion on supports(L1_(2)-Pt_3Co_(x)Mn_(1-x)/~SPt INPs/C).Electrochemical results present that the composition-optimized L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C exhibits the highest electrocata lytic activity among the series,which are also much better than those of the pristine ultrafine Pt/C.Besides,it also has a greatly enhanced electrochemical stability.In addition,the effects of annealing temperature and time are further investigated.More importantly,such superior ORR electrocatalytic performance of L1_(2)-Pt_3Co_(0.7)Mn_(0.3)/~SPt INPs/C are also well demonstrated in practical fuel cells.Physicochemical characterization analyses further reveal the major origins of the greatly enhanced ORR electrocata lytic performance:the Pt-Co-Mn alloy-induced geometric and ligand effects as well as the extremely high L1_(2) atomic-ordering degree.This work not only successfully develops a highly active and stable ordered ternary intermetallic ORR electrocatalyst,but also elucidates the corresponding"structure-function"relationship,which can be further applied in designing other intermetallic(electro)catalysts.
基金supported by the Natural Science Foundation of Tibet Autonomous Region(XZ202201ZR0012G)Quality Evaluation and Efficient Utilization of Effective Components of Potentilla anserine Resources in Tibet(XZ202201ZD0001N).
文摘Potentilla anserina L.(PA)belongs to the Rosaceae family,is a common edible plant in the Qinghai-Tibet Plateau areas of China.This study elucidates the mechanism upon which crude polysaccharide of PA(PAP)on fat accumulation in HepG2 cells stimulated by oleic acid(OA)and high fat high sugar induced mice.The result revealed that PAP inhibited lipid accumulation in obese mice and ameliorated the degree of damage in OA-induced HepG2 cells.Specifically,compared to the control group,the TG and TC levels were decreased in cells and mice serum,the aspartate transaminase and alamine aminotransferase contents were declined in liver of obese mice by PAP treatment.The expressions of adipogenic genes of SREBP-1c,C/EBPα,PPARγ,and FAS were inhibited after PAP treatment.Moreover,PAP increased the mRNA levels of CPT-1 and PPARα,which were involved in fatty acid oxidation.The present results indicated the PAP could alleviate the damage of liver associated with obesity and PAP treatment might provide a dietary therapeutic option for the treatment of hyperlipidemia.
