发展一种高质量活性的高效水分解催化剂对于实现大规模制氢来说至关重要,但目前这仍是一个巨大的挑战.我们报道了简便的一锅法来合成一系列核@壳Ni@Ru M(M=Ni or Co)纳米晶(NCs),并将其用于高效催化水分解,该系列催化剂均以金属Ni为核,...发展一种高质量活性的高效水分解催化剂对于实现大规模制氢来说至关重要,但目前这仍是一个巨大的挑战.我们报道了简便的一锅法来合成一系列核@壳Ni@Ru M(M=Ni or Co)纳米晶(NCs),并将其用于高效催化水分解,该系列催化剂均以金属Ni为核,壳层则是组分可调控的RuM(M=NiorCo)合金.在这些催化剂中,Ni@Ru Ni NCs对催化产氢表现出优异的性能,在过电位为0.7 V(vs.RHE)时,其质量活性高达1590mAmgRu^-1,是同等条件下商业Pt/C的1.7倍(950mAmgPt^-1).而对于产氧反应来说,质量活性最高的则是Ni@Ru0.4Co0.6NCs,在电位为1.56 V vs.RHE时,其质量活性达270 mAmgRu^-1,远远超过了商业RuO2(89 m A mgRu^-1).这些催化剂优异的质量活性归因于它们的核@壳结构,壳层中金属Ru通过与金属Ni或者Co形成合金来调控自身的电子结构,使其更有利于产氢/氧反应的进行.展开更多
The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)b...The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)bimetallic nano-branched structure(NBs)by a simple high temperature solution-phase synthesis.As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface,which promote them favorable bifunctional catalytic properties in acidic electrolytes,specifically in terms of the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).Specially,Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity(SA)and mass activity(MA)for ORR than state-of-the-art commercial Pt/C catalysts,respectively.Moreover,it exhibits a loss of 4.0%in SA and 14.4%in MA after 10,000 cycles of accelerated durability tests(ADTs)compared with the initial activities.In addition,we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes.For Pt-M NBs with other alloying metals,the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C>Pt-Fe/C>Pt-Ni/C>commercial Pt/C(or PtRu/C).The improved activities and durability can benefit from the morphological and compositional effects.This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.展开更多
基金funding from the National Natural Science Foundation of China (21427811, 21721003 and 51671003)the Ministry of Science and Technology, China (2016YFA0203200)+1 种基金the Youth Innovation Promotion Association CAS (2016208)Jilin Province Science Technology Development Plan Project (20170101194JC)
文摘发展一种高质量活性的高效水分解催化剂对于实现大规模制氢来说至关重要,但目前这仍是一个巨大的挑战.我们报道了简便的一锅法来合成一系列核@壳Ni@Ru M(M=Ni or Co)纳米晶(NCs),并将其用于高效催化水分解,该系列催化剂均以金属Ni为核,壳层则是组分可调控的RuM(M=NiorCo)合金.在这些催化剂中,Ni@Ru Ni NCs对催化产氢表现出优异的性能,在过电位为0.7 V(vs.RHE)时,其质量活性高达1590mAmgRu^-1,是同等条件下商业Pt/C的1.7倍(950mAmgPt^-1).而对于产氧反应来说,质量活性最高的则是Ni@Ru0.4Co0.6NCs,在电位为1.56 V vs.RHE时,其质量活性达270 mAmgRu^-1,远远超过了商业RuO2(89 m A mgRu^-1).这些催化剂优异的质量活性归因于它们的核@壳结构,壳层中金属Ru通过与金属Ni或者Co形成合金来调控自身的电子结构,使其更有利于产氢/氧反应的进行.
基金This work was supported by the National Natural Science Foundation of China(Nos.51571072 and 51871078)Heilongjiang Science Foundation(No.E2018028)the China Scholarship Council,and the NSF MRSEC Program(DMR-14-19807).
文摘The morphology and size of Pt-based bimetallic alloys are known to determine their electrocatalytic performance in reactions relevant to fuel cells.Here,we report a general approach for preparing Pt-M(M=Fe,Co and Ni)bimetallic nano-branched structure(NBs)by a simple high temperature solution-phase synthesis.As-prepared Pt-M NBs show a polycrystalline structure and are rich in steps and kinks on the surface,which promote them favorable bifunctional catalytic properties in acidic electrolytes,specifically in terms of the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).Specially,Pt-Co NBs/C catalyst shows 6.1 and 5.3 times higher in specific activity(SA)and mass activity(MA)for ORR than state-of-the-art commercial Pt/C catalysts,respectively.Moreover,it exhibits a loss of 4.0%in SA and 14.4%in MA after 10,000 cycles of accelerated durability tests(ADTs)compared with the initial activities.In addition,we also confirmed the superior MOR activity of Pt-Co NBs/C catalyst in acidic electrolytes.For Pt-M NBs with other alloying metals,the ORR and MOR activities are both higher than commercial catalysts and are in the sequence of Pt-Co/C>Pt-Fe/C>Pt-Ni/C>commercial Pt/C(or PtRu/C).The improved activities and durability can benefit from the morphological and compositional effects.This synthesis approach may be applied to develop bifunctional catalysts with enhanced ORR and MOR properties for future fuel cells designs.
