High-performance Pt catalysts supported on hierarchical nitrogen-doped carbon nanocages for methanol electrooxidation

Article abstract of DOI:10.1016/S1872-2067(15)61117-2

Hierarchical nitrogen-doped carbon nanocages (hNCNC) with large specific surface areas were used as a catalyst support to immobilize Pt nanoparticles by a microwave-assisted polyol method. The Pt/hNCNC catalyst with 20 wt% loading has a homogeneous dispersion of Pt nanoparticles with the average size of 3.3 nm, which is smaller than 4.3 and 4.9 nm for the control catalysts with the same loading supported on hierarchical carbon nanocages (hCNC) and commercial Vulcan XC-72, respectively. Accordingly, Pt/hNCNC has a larger electrochemical surface area than Pt/hCNC and Pt/XC-72. The Pt/hNCNC catalyst exhibited excellent electrocatalytic activity and stability for methanol oxidation, which was better than the control catalysts. This was attributed to the enhanced interaction between Pt and hNCNC due to nitrogen participation in the anchoring function. By making use of the unique advantages of the hNCNC support, a heavy Pt loading up to 60 wt% was prepared without serious agglomeration, which gave a high peak-current density per unit mass of catalyst of 95.6 mA/mg for achieving a high power density. These results showed the potential of the Pt/hNCNC catalyst for methanol oxidation and of the new hNCNC support for wide applications.

Full text of DOI:10.1016/S1872-2067(15)61117-2

ChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155
ꢀ
ꢀ ꢀ ꢀ
ꢀ ꢀ ꢀ ꢀ
a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
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j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
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ꢀ
Article (Special Issue on Electrocatalysis Transformation)
High‐performanceꢀPtꢀcatalystsꢀsupportedꢀonꢀhierarchicalꢀ ꢀ
nitrogen‐dopedꢀcarbonꢀnanocagesꢀforꢀmethanolꢀelectrooxidationꢀ
ꢀ
a,b
ꢀa
ꢀa
ꢀa
ꢀa
ꢀa
XiangfenꢀJiang ,ꢀXuebinꢀWang ,ꢀLimingꢀShen ,ꢀQiangꢀWu ,ꢀYangnianꢀWang ,ꢀYanwenꢀMa ,ꢀ ꢀ
ꢀa,
ꢀa,#
XizhangꢀWang *,ꢀZhengꢀHu
ꢀ
aꢀKeyꢀLaboratoryꢀofꢀMesoscopicꢀChemistryꢀofꢀMOE,ꢀSchoolꢀofꢀChemistryꢀandꢀChemicalꢀEngineering,ꢀNanjingꢀUniversity,ꢀNanjingꢀ210093,ꢀJiangsu,ꢀChinaꢀ
bꢀInternationalꢀCenterꢀforꢀMaterialsꢀNanoarchitectonicsꢀ(MANA),ꢀNationalꢀInstituteꢀforꢀMaterialsꢀScienceꢀ(NIMS),ꢀTsukubaꢀ3050044,ꢀJapanꢀ
A R T I C L E ꢀ I N F O ꢀ
A B S T R A C T ꢀ
Articleꢀhistory:ꢀ
Hierarchicalꢀnitrogen‐dopedꢀcarbonꢀnanocagesꢀ(hNCNC)ꢀwithꢀlargeꢀspecificꢀsurfaceꢀareasꢀwereꢀusedꢀ
asꢀaꢀcatalystꢀsupportꢀtoꢀimmobilizeꢀPtꢀnanoparticlesꢀbyꢀaꢀmicrowave‐assistedꢀpolyolꢀmethod.ꢀTheꢀ
Pt/hNCNCꢀcatalystꢀwithꢀ20ꢀwt%ꢀloadingꢀhasꢀaꢀhomogeneousꢀdispersionꢀofꢀPtꢀnanoparticlesꢀwithꢀtheꢀ
averageꢀsizeꢀofꢀ3.3ꢀnm,ꢀwhichꢀisꢀsmallerꢀthanꢀ4.3ꢀandꢀ4.9ꢀnmꢀforꢀtheꢀcontrolꢀcatalystsꢀwithꢀtheꢀsameꢀ
loadingꢀsupportedꢀonꢀhierarchicalꢀcarbonꢀnanocagesꢀ(hCNC)ꢀandꢀcommercialꢀVulcanꢀXC‐72,ꢀrespec‐
tively.ꢀ Accordingly,ꢀ Pt/hNCNCꢀ hasꢀ aꢀ largerꢀ electrochemicalꢀ surfaceꢀ areaꢀ thanꢀ Pt/hCNCꢀ andꢀ
Pt/XC‐72.ꢀ Theꢀ Pt/hNCNCꢀ catalystꢀ exhibitedꢀ excellentꢀ electrocatalyticꢀ activityꢀ andꢀ stabilityꢀ forꢀ
methanolꢀ oxidation,ꢀ whichꢀ wasꢀ betterꢀ thanꢀ theꢀ controlꢀ catalysts.ꢀ Thisꢀ wasꢀ attributedꢀ toꢀ theꢀ en‐
hancedꢀinteractionꢀbetweenꢀPtꢀandꢀhNCNCꢀdueꢀtoꢀnitrogenꢀparticipationꢀinꢀtheꢀanchoringꢀfunction.ꢀ
ByꢀmakingꢀuseꢀofꢀtheꢀuniqueꢀadvantagesꢀofꢀtheꢀhNCNCꢀsupport,ꢀaꢀheavyꢀPtꢀloadingꢀupꢀtoꢀ60ꢀwt%ꢀ
wasꢀpreparedꢀwithoutꢀseriousꢀagglomeration,ꢀwhichꢀgaveꢀaꢀhighꢀpeak‐currentꢀdensityꢀperꢀunitꢀmassꢀ
ofꢀcatalystꢀofꢀ95.6ꢀmA/mgꢀforꢀachievingꢀaꢀhighꢀpowerꢀdensity.ꢀTheseꢀresultsꢀshowedꢀtheꢀpotentialꢀofꢀ
theꢀPt/hNCNCꢀcatalystꢀforꢀmethanolꢀoxidationꢀandꢀofꢀtheꢀnewꢀhNCNCꢀsupportꢀforꢀwideꢀapplications.
Receivedꢀ30ꢀMarchꢀ2016ꢀ
Acceptedꢀ18ꢀAprilꢀ2016ꢀ
Publishedꢀ5ꢀJulyꢀ2016ꢀ
Keywords:ꢀ
Methanolꢀoxidationꢀ
Fuelꢀcellsꢀ
Platinumꢀcatalystꢀ
Hierarchicalꢀnitrogen‐dopedꢀcarbonꢀ
ꢀ
ꢀ nanocagesꢀ
Highꢀperformanceꢀ
©ꢀ2016,ꢀDalianꢀInstituteꢀofꢀChemicalꢀPhysics,ꢀChineseꢀAcademyꢀofꢀSciences.
PublishedꢀbyꢀElsevierꢀB.V.ꢀAllꢀrightsꢀreserved.
1
.ꢀ ꢀ Introductionꢀ
stableꢀ structureꢀ willꢀ leadꢀ toꢀ highꢀ dispersion,ꢀ highꢀ utilizationꢀ
andꢀstabilityꢀofꢀPtꢀnanoparticlesꢀandꢀovercomeꢀtheseꢀobstaclesꢀ
[3].ꢀ Carbonꢀ materialsꢀ withꢀ highꢀ specificꢀ surfaceꢀ areasꢀ (SSAs)ꢀ
areꢀgoodꢀsupportsꢀinꢀDMFCsꢀ dueꢀtoꢀtheirꢀhighꢀelectricalꢀ con‐
ductivity,ꢀcorrosionꢀresistance,ꢀandꢀlowꢀcostꢀ[3,4].ꢀApartꢀfromꢀ
commercialꢀ activatedꢀ carbonꢀ supports,ꢀ e.g.,ꢀ Valcanꢀ XC‐72ꢀ [5],ꢀ
whichꢀusuallyꢀengulfꢀaꢀlotꢀofꢀPtꢀinꢀtheirꢀprimaryꢀmicroporesꢀandꢀ
thusꢀ causeꢀ someꢀ catalyticꢀ activityꢀ loss,ꢀ severalꢀ novelꢀ carbonꢀ
nanomaterialsꢀsuchꢀasꢀcarbonꢀnanotubesꢀ[6],ꢀcarbonꢀnanofibersꢀ
Directꢀ methanolꢀ fuelꢀ cellsꢀ (DMFCs)ꢀ haveꢀ attractedꢀ consid‐
erableꢀattentionꢀasꢀidealꢀcandidatesꢀforꢀautomotiveꢀandꢀporta‐
bleꢀapplicationsꢀdueꢀtoꢀtheꢀadvantagesꢀofꢀhighꢀenergyꢀconver‐
sionꢀefficiencyꢀandꢀabilityꢀtoꢀbeꢀeasilyꢀhandledꢀ[1].ꢀTheꢀmajorꢀ
obstaclesꢀ toꢀ DMFCꢀ practicalꢀ applicationꢀ areꢀ theꢀ lowꢀ catalyticꢀ
performance,ꢀhighꢀcost,ꢀandꢀpoorꢀdurabilityꢀofꢀtheꢀnobleꢀmetalꢀ
catalystsꢀ[2].ꢀAꢀcatalystꢀsupportꢀwithꢀaꢀlargeꢀsurfaceꢀareaꢀandꢀ
*
ꢀ
ꢀCorrespondingꢀauthor.ꢀTel/Fax:ꢀ+86‐25‐89683696;ꢀE‐mail:ꢀwangxzh@nju.edu.cnꢀ
Correspondingꢀauthor.ꢀTel/Fax:ꢀ+86‐25‐89686015;ꢀE‐mail:ꢀzhenghu@nju.edu.cnꢀ ꢀ
#
ThisꢀworkꢀwasꢀsupportedꢀbyꢀtheꢀNationalꢀNaturalꢀScienceꢀFoundationꢀofꢀChinaꢀ(21473089,ꢀ51232003,ꢀ21373108,ꢀ51571110,ꢀ21573107),ꢀtheꢀNation‐
alꢀBasicꢀResearchꢀProgramꢀofꢀChinaꢀ(973ꢀProgram,ꢀ2013CB932902),ꢀSuzhouꢀScienceꢀandꢀTechnologyꢀProjectsꢀ(ZXG2013025),ꢀandꢀChangzhouꢀScienceꢀ
andꢀTechnologyꢀProjectsꢀ(CE20130032).ꢀThisꢀworkꢀwasꢀalsoꢀsupportedꢀbyꢀaꢀProjectꢀFundedꢀbyꢀtheꢀTechnologyꢀSupportꢀPriorityꢀAcademicꢀProgramꢀ
DevelopmentꢀofꢀJiangsuꢀHigherꢀEducationꢀInstitutions.ꢀ
DOI:ꢀ10.1016/S1872‐2067(15)61117‐2ꢀ|ꢀhttp://www.sciencedirect.com/science/journal/18722067ꢀ|ꢀChin.ꢀJ.ꢀCatal.,ꢀVol.ꢀ37,ꢀNo.ꢀ7,ꢀJulyꢀ2016ꢀ ꢀ ꢀ

1150ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
[7],ꢀcarbonꢀnanocoinsꢀ[8]ꢀandꢀgrapheneꢀ[9]ꢀhaveꢀalsoꢀbeenꢀex‐
2.2.ꢀ ꢀ Characterizationꢀ
plored.ꢀOwingꢀtoꢀtheꢀsurfaceꢀinertness,ꢀsurfaceꢀmodificationꢀareꢀ
usuallyꢀusedꢀtoꢀintroduceꢀanchoringꢀsites,ꢀe.g.,ꢀbyꢀacidꢀoxidationꢀ
andꢀcovalentꢀgraftingꢀ[10,11].ꢀHowever,ꢀtheseꢀmethodsꢀusuallyꢀ
involveꢀcomplexꢀprocessesꢀandꢀinevitablyꢀdamageꢀtheꢀstructur‐
al,ꢀ mechanical,ꢀ andꢀ electricalꢀ properties.ꢀ Alternatively,ꢀ inꢀ situꢀ
nitrogenꢀdopingꢀintoꢀtheꢀcarbonꢀmatrixꢀduringꢀgrowthꢀcanꢀin‐
troduceꢀchemicallyꢀactiveꢀsitesꢀforꢀanchoringꢀmetalꢀandꢀmetalꢀ
oxideꢀ nanoparticlesꢀ [12–18].ꢀ Ourꢀ studiesꢀ indicatedꢀ thatꢀ
Pt‐basedꢀnanoparticlesꢀcouldꢀbeꢀeasilyꢀandꢀuniformlyꢀimmobi‐
lizedꢀ onꢀ N‐dopedꢀ carbonꢀ nanotubesꢀ (NCNTs),ꢀ andꢀ theseꢀ
showedꢀ enhancedꢀ electrocatalyticꢀ performanceꢀ forꢀ methanolꢀ
oxidationꢀandꢀoxygenꢀreductionꢀ[13–15].ꢀHowever,ꢀtheꢀSSAꢀofꢀ
Theꢀstructureꢀandꢀcompositionꢀofꢀtheꢀcatalystsꢀwereꢀchar‐
acterizedꢀbyꢀhighꢀresolutionꢀtransmissionꢀelectronꢀmicroscopyꢀ
(HRTEM,ꢀ JEM‐2100ꢀ operatingꢀ atꢀ 200ꢀ kV),ꢀ scanningꢀ electronꢀ
microscopyꢀ (SEM,ꢀ Hitachiꢀ S4800),ꢀ X‐rayꢀ diffractionꢀ (XRD,ꢀ
PhilipsꢀX’pertꢀ ProꢀX‐rayꢀ diffractometer),ꢀandꢀX‐rayꢀ photoelec‐
tronꢀspectroscopyꢀ(XPS,ꢀULVAC‐PHIꢀINC,ꢀPHIꢀ5000ꢀVersaProbe,ꢀ
AlꢀK ).ꢀThermogravimetryꢀ(TG,ꢀNETZSCHꢀSTA449F3)ꢀwasꢀcar‐

riedꢀoutꢀinꢀairꢀflowꢀatꢀaꢀrateꢀofꢀ10.0ꢀ°C/min.ꢀN ꢀadsorptionꢀiso‐
2
thermsꢀwereꢀmeasuredꢀonꢀMicromeriticsꢀASAPꢀ2020ꢀatꢀ–196ꢀ°Cꢀ
withꢀtheꢀspecimensꢀdegassedꢀatꢀ300ꢀ°Cꢀforꢀ4ꢀh.ꢀ
2
theꢀNCNTsꢀisꢀusuallyꢀnotꢀlargeꢀenough,ꢀasꢀitꢀisꢀonlyꢀ200ꢀm /g.ꢀ
2.3.ꢀ ꢀ Electrochemicalꢀmeasurementꢀ
Veryꢀrecently,ꢀbyꢀanꢀinꢀsituꢀMgOꢀtemplateꢀmethod,ꢀweꢀreportedꢀ
uniqueꢀ 3Dꢀhierarchicalꢀcarbon‐basedꢀnanocagesꢀthatꢀ featuredꢀ
highꢀ SSAsꢀ upꢀ toꢀ 1400ꢀ m /gꢀ andꢀ goodꢀ conductivityꢀ [19–23],ꢀ
Theꢀelectrochemicalꢀperformancesꢀwereꢀcharacterizedꢀbyꢀaꢀ
2
CHIꢀ760Cꢀworkstationꢀ(CHꢀInstrument,ꢀInc.)ꢀwithꢀaꢀthree‐elec‐
ꢀ
whichꢀ exhibitedꢀ excellentꢀ electrochemicalꢀ performances.ꢀ Byꢀ
usingꢀ hierarchicalꢀ N‐dopedꢀ carbonꢀ nanocagesꢀ (hNCNC)ꢀ asꢀ aꢀ
newꢀsupport,ꢀhereꢀweꢀreportꢀtheꢀhighꢀdispersionꢀofꢀaꢀPtꢀelec‐
trocatalystꢀonꢀhNCNCꢀmadeꢀbyꢀaꢀmodifiedꢀmicrowave‐assistedꢀ
polyolꢀ method.ꢀ Theꢀ constructedꢀ Pt/hNCNCꢀ demonstratedꢀ ex‐
cellentꢀelectrochemicalꢀactivityꢀandꢀgoodꢀstabilityꢀforꢀmethanolꢀ
oxidation,ꢀwhichꢀwereꢀsuperiorꢀtoꢀthoseꢀofꢀtheirꢀcounterpartsꢀ
supportedꢀonꢀcarbonꢀnanocagesꢀandꢀcommercialꢀVulcanꢀXC‐72.ꢀ
Bothꢀ theꢀ strongꢀ interactionꢀ betweenꢀ Ptꢀ andꢀ hNCNCꢀ andꢀ theꢀ
excellentꢀ dispersionꢀ ofꢀ Ptꢀ byꢀ nitrogenꢀ incorporationꢀ wereꢀ re‐
sponsibleꢀforꢀtheꢀenhancedꢀperformanceꢀinꢀmethanolꢀelectro‐
catalyticꢀoxidation.ꢀThisꢀilluminatesꢀtheꢀapplicationꢀofꢀhNCNCꢀinꢀ
theꢀfieldꢀofꢀDMFCs.ꢀ
trodeꢀsystemꢀatꢀ25ꢀ°C.ꢀAg/AgClꢀandꢀaꢀplatinumꢀthreadꢀservedꢀasꢀ
theꢀ referenceꢀ andꢀ counterꢀ electrodes,ꢀ respectively.ꢀ Theꢀ workꢀ
electrodeꢀwasꢀaꢀthinꢀfilmꢀelectrodeꢀwithꢀtheꢀcatalystꢀcastedꢀonꢀaꢀ
glassyꢀcarbonꢀdiskꢀofꢀ3.0ꢀmmꢀinꢀdiameter.ꢀTypically,ꢀaꢀsuspen‐
sionꢀ ofꢀ catalystꢀ (4.0ꢀ mg/mL)ꢀ wasꢀ preparedꢀ byꢀ ultrasonicallyꢀ
dispersingꢀ 2.0ꢀ mgꢀ catalystꢀ inꢀ 400ꢀ μLꢀ ethanol/waterꢀ solutionꢀ
(1/2,ꢀV/V)ꢀandꢀ100ꢀμLꢀNafionꢀsolutionꢀ(5ꢀwt%ꢀNafion,ꢀAlfaꢀAe‐
sar).ꢀThenꢀtheꢀ10ꢀμLꢀsuspensionꢀwasꢀdroppedꢀontoꢀtheꢀglassyꢀ
carbonꢀdiskꢀtoꢀconstructꢀaꢀthinꢀfilmꢀelectrode.ꢀCyclicꢀvoltamme‐
tryꢀ(CV)ꢀofꢀhydrogenꢀelectrochemicalꢀadsorptionꢀwasꢀmeasuredꢀ
inꢀ N
1.0ꢀVꢀatꢀaꢀscanꢀrateꢀofꢀ50ꢀmV/s.ꢀCOꢀstrippingꢀCVꢀwasꢀmeasuredꢀ
inꢀ0.5ꢀmol/LꢀH SO ꢀsolutionꢀafterꢀCOꢀbubblingꢀforꢀ15ꢀminꢀbe‐
2
‐saturatedꢀ0.5ꢀmol/LꢀH
2
SO ꢀ solutionꢀbetweenꢀ 0.23ꢀ andꢀ
4
2
4
tweenꢀ0ꢀandꢀ1.25ꢀVꢀatꢀaꢀscanꢀrateꢀofꢀ10ꢀmV/s.ꢀTheꢀelectrocata‐
lyticꢀ CVꢀ forꢀ methanolꢀ oxidationꢀ wasꢀ performedꢀ inꢀ 1.0ꢀ mol/Lꢀ
2.ꢀ ꢀ Experimentalꢀ
methanolꢀandꢀ0.5ꢀmol/LꢀH
2
SO ꢀsolutionꢀinꢀtheꢀpotentialꢀrangeꢀ
4
2
.1.ꢀ ꢀ ConstructionꢀofꢀtheꢀPt‐basedꢀcatalystsꢀ
ofꢀ0–1.0ꢀVꢀatꢀaꢀscanꢀrateꢀofꢀ50ꢀmV/s.ꢀTheꢀstabilityꢀofꢀtheꢀcata‐
lystsꢀ wasꢀ evaluatedꢀ byꢀ chronoamperometryꢀ atꢀ 0.60ꢀ Vꢀ forꢀ
2000ꢀs.ꢀ
hNCNCꢀwasꢀpreparedꢀbyꢀtheꢀinꢀsituꢀMgOꢀtemplateꢀmethodꢀ
developedꢀ recentlyꢀ byꢀ ourꢀ groupꢀ [20,21],ꢀ whichꢀ isꢀ character‐
izedꢀbyꢀco‐existingꢀmicro‐meso‐macropores,ꢀgoodꢀconductivity,ꢀ
andꢀaꢀlargeꢀSSAꢀgenerallyꢀupꢀtoꢀ1400ꢀm /g.ꢀBriefly,ꢀbasicꢀmag‐
3.ꢀ ꢀ Resultsꢀandꢀdiscussionꢀ
2
nesiumꢀcarbonateꢀ(4ꢀg)ꢀwasꢀplacedꢀinꢀaꢀquartzꢀtubeꢀandꢀheatedꢀ
toꢀ900ꢀ°C.ꢀThenꢀ1.8ꢀmLꢀpyridineꢀwasꢀintroducedꢀintoꢀtheꢀreac‐
torꢀ atꢀ theꢀ feedingꢀ rateꢀ ofꢀ 60ꢀ μL/minꢀ byꢀ aꢀ syringeꢀ pump.ꢀ Se‐
quentially,ꢀ theꢀ MgOꢀ templateꢀ wasꢀ removedꢀ byꢀ 1ꢀ mol/Lꢀ HClꢀ
aqueousꢀsolution.ꢀFinally,ꢀhNCNCꢀwithꢀ8ꢀat%ꢀnitrogenꢀdopingꢀ
wasꢀ obtainedꢀ afterꢀ washingꢀ repeatedlyꢀ withꢀ deionizedꢀ waterꢀ
andꢀdryingꢀatꢀ110ꢀ°C.ꢀPtꢀparticlesꢀwereꢀsupportedꢀonꢀhNCNCꢀbyꢀ
aꢀ modifiedꢀ microwave‐assistedꢀ polyolꢀ processꢀ [24].ꢀ Typically,ꢀ
Fig.ꢀ1ꢀdisplaysꢀSEMꢀandꢀTEMꢀimagesꢀofꢀPt/hNCNC,ꢀPt/hCNCꢀ
andꢀPt/XC‐72.ꢀPtꢀparticlesꢀwereꢀhomogenouslyꢀimmobilizedꢀonꢀ
hNCNCꢀ withꢀ theꢀ averageꢀ sizeꢀ ofꢀ 3.3ꢀ nm,ꢀ whichꢀ wasꢀ slightlyꢀ
smallerꢀ thanꢀ 4.3ꢀ nmꢀ forꢀ Pt/hCNCꢀ andꢀ 4.9ꢀ nmꢀ forꢀ Pt/XC‐72,ꢀ
whichꢀindicatedꢀtheꢀbetterꢀdispersionꢀonꢀhNCNCꢀthanꢀonꢀhCNCꢀ
andꢀ XC‐72ꢀ dueꢀ toꢀ theꢀ nitrogenꢀ participationꢀ asꢀ expectedꢀ
[13–15].ꢀTheꢀinterplanarꢀspacingꢀofꢀ0.226ꢀnmꢀcorrespondedꢀtoꢀ
d111ꢀofꢀ(fcc)ꢀPtꢀ(PDFꢀ88‐2343).ꢀTheꢀthreeꢀcatalystsꢀwereꢀfurtherꢀ
2
5.0ꢀ mgꢀ hNCNCꢀ wasꢀ ultrasonicallyꢀ dispersedꢀ inꢀ 50.0ꢀ mLꢀ eth‐
characterizedꢀbyꢀTGꢀandꢀXRD.ꢀTheꢀresultsꢀareꢀpresentedꢀinꢀFig.ꢀ
2.ꢀ Theꢀ Ptꢀ loadingsꢀ wereꢀ obtainedꢀ toꢀ beꢀ 21.6,ꢀ 21.2,ꢀ andꢀ 19.0ꢀ
wt%,ꢀrespectively,ꢀcloseꢀtoꢀtheꢀ23.1ꢀwt%ꢀPtꢀnominalꢀvalueꢀ(Fig.ꢀ
2(a)).ꢀTheꢀPtꢀparticlesꢀwereꢀassignedꢀtoꢀ(fcc)ꢀPtꢀ(PDFꢀ88‐2343).ꢀ
Theꢀd111ꢀspacingꢀofꢀtheꢀpeaksꢀatꢀ39.8°ꢀ(Fig.ꢀ2(b))ꢀwasꢀinꢀagree‐
mentꢀwithꢀtheꢀTEMꢀfringesꢀ(Fig.ꢀ1).ꢀ ꢀ
XPSꢀspectraꢀofꢀtheꢀcatalystsꢀareꢀshownꢀinꢀFig.ꢀ3.ꢀTheꢀPtꢀ4fꢀ
peaksꢀcanꢀbeꢀdeconvolutedꢀintoꢀthreeꢀPtꢀspecies,ꢀi.e.,ꢀPt(0)ꢀ(71.2ꢀ
eV),ꢀPt(II)ꢀ(72.4ꢀeV)ꢀandꢀPt(IV)ꢀ(74.4ꢀeV)ꢀforꢀPtꢀ4f7/2ꢀ[25],ꢀwithꢀ
theꢀ correspondingꢀ ratioꢀ ofꢀ 60.3:30.8:8.9ꢀ forꢀ Pt/hNCNC.ꢀ Thus,ꢀ
yleneꢀ glycolꢀ (EG).ꢀ Thenꢀ 1.0ꢀ mLꢀ H
2
PtCl /EGꢀ solutionꢀ (7.5ꢀ mgꢀ
6
ꢀ
Pt/mLꢀ EG)ꢀ andꢀ 0.25ꢀ mL NaOH/EGꢀ solutionꢀ (0.2ꢀ mol/L)ꢀ wereꢀ
droppedꢀ intoꢀ theꢀ suspensionꢀ underꢀ magneticꢀ stirring.ꢀ Afterꢀ
irradiatingꢀwithꢀaꢀdomesticꢀmicrowaveꢀovenꢀ(800ꢀW)ꢀforꢀ100ꢀs,ꢀ
Pt/hNCNCꢀ withꢀ aꢀ nominalꢀ loadingꢀ ofꢀ 23ꢀ wt%ꢀ wasꢀ obtainedꢀ
afterꢀfiltrating,ꢀrinsing,ꢀandꢀdryingꢀunderꢀvacuumꢀforꢀ12ꢀh.ꢀForꢀ
comparison,ꢀ hierarchicalꢀ carbonꢀ nanocagesꢀ (hCNC)ꢀ fromꢀ aꢀ
benzeneꢀ precursorꢀ andꢀ Valcanꢀ XC‐72ꢀ wereꢀ alsoꢀ usedꢀ asꢀ theꢀ
supportꢀtoꢀprepareꢀPt/hCNCꢀandꢀPt/XC‐72ꢀinꢀaꢀsimilarꢀway.ꢀ

ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
1151ꢀ
(
a)
(b)
0.226 nm
5
0 nm
20 nm
2
3 4 5 6 7
Particle size (nm)
(
c)
(d)
0.227 nm
5
0 nm
20 nm
2
3 4 5 6 7
Particle size (nm)
(
e)
(f)
0
.226 nm
5
0 nm
20 nm
2
3
4 5 6 7
Particle size (nm)
Fig.ꢀ1.ꢀSEMꢀandꢀTEMꢀimagesꢀofꢀPt/hNCNCꢀ(a,b),ꢀPt/hCNCꢀ(c,d),ꢀandꢀPt/XC‐72ꢀ(e,f).ꢀTheꢀinsertsꢀareꢀtheꢀcorrespondingꢀHRTEMꢀimagesꢀandꢀparticleꢀsize
histogramsꢀfromꢀ400ꢀPtꢀnanoparticles.ꢀ
(a)
(b)



Pt
1
00

Graphite
Pt/hNCNC
Pt/hCNC
Pt/XC-72

8
6
4
2
0
0
0
0
0


Pt/hNCNC
Pt/hCNC
Pt/XC-72
20
100
200
300
400
o
500
600
40
60
80
o
Temperature ( C)
2 /(
)
Fig.ꢀ2.ꢀTGꢀcurvesꢀ(a)ꢀandꢀXRDꢀpatternsꢀ(b)ꢀofꢀPt/hNCNC,ꢀPt/hCNC,ꢀandꢀPt/XC‐72.ꢀ
theꢀPtꢀspeciesꢀexistꢀpredominantlyꢀasꢀmetallicꢀPt(0)ꢀinꢀtheꢀthreeꢀ
catalystsꢀ(Fig.ꢀ3(b)–(d)).ꢀTheꢀtotalꢀPtꢀcontentsꢀwereꢀcharacter‐
izedꢀtoꢀbeꢀ23.0,ꢀ22.3ꢀandꢀ20.1ꢀwt%ꢀinꢀPt/NCNC,ꢀPt/hCNCꢀandꢀ
Pt/XC‐72,ꢀ respectively,ꢀ whichꢀ wereꢀ closeꢀ toꢀ theꢀ TGꢀ analysisꢀ
resultsꢀ(Fig.ꢀ2(a)).ꢀ
XRDꢀ characterizationꢀ (Fig.ꢀ 1,ꢀ Fig.ꢀ 2(b)).ꢀ Theseꢀ resultsꢀ clearlyꢀ
indicatedꢀ theꢀ Ptꢀ dispersionꢀ wasꢀ inꢀ theꢀ orderꢀ ofꢀ Pt/hNCNCꢀ >ꢀ
Pt/hCNCꢀ>ꢀPt/XC‐72.ꢀ ꢀ
Theꢀelectrocatalyticꢀactivityꢀandꢀstabilityꢀofꢀtheꢀcatalystsꢀforꢀ
methanolꢀ oxidationꢀ wereꢀ evaluatedꢀ byꢀ CVꢀ andꢀ chronoam‐
perometryꢀmeasurements,ꢀwithꢀtheꢀcurrentꢀ densitiesꢀnormal‐
izedꢀ byꢀ Ptꢀ loading,ꢀ asꢀ shownꢀ inꢀ Fig.ꢀ 5.ꢀ Theꢀ typicalꢀ methanolꢀ
oxidationꢀpeakꢀappearedꢀinꢀtheꢀforwardꢀsweepꢀatꢀ0.64ꢀV.ꢀTheꢀ
oxidationꢀpeakꢀinꢀtheꢀbackwardꢀsweepꢀatꢀca.ꢀ0.42ꢀVꢀrepresentedꢀ
theꢀ removalꢀ ofꢀ incompletelyꢀ oxidizedꢀ carbonaceousꢀ speciesꢀ
formedꢀinꢀtheꢀforwardꢀsweepꢀ[26,27].ꢀTheꢀpeakꢀcurrentꢀdensityꢀ
ofꢀPt/hNCNCꢀreachedꢀ342ꢀmA/mgPt@0.64V,ꢀwhichꢀwasꢀsignifi‐
Theꢀelectrochemicalꢀsurfaceꢀareaꢀ(ECSA)ꢀofꢀPtꢀinꢀPt/hNCNC,ꢀ
Pt/hCNCꢀandꢀPt/XC‐72ꢀwereꢀmeasuredꢀbyꢀCVꢀtestsꢀofꢀhydrogenꢀ
adsorptionꢀandꢀCOꢀstripping,ꢀasꢀillustratedꢀinꢀFig.ꢀ4.ꢀECSA
obtainedꢀtoꢀbeꢀ45.6,ꢀ34.2ꢀandꢀ24.2ꢀm /g,ꢀandꢀECSACOꢀtoꢀbeꢀ50.7,ꢀ
H
ꢀwereꢀ
2
2
3
4.3ꢀandꢀ21.8ꢀm /g,ꢀrespectively.ꢀBothꢀresultsꢀshowedꢀtheꢀECSAꢀ
orderꢀ ofꢀ Pt/hNCNCꢀ >ꢀ Pt/hCNCꢀ >ꢀ Pt/XC‐72,ꢀ whichꢀ wasꢀ con‐
sistentꢀ withꢀ theꢀ sizeꢀ orderꢀ ofꢀ theꢀ Ptꢀ particlesꢀ fromꢀ TEMꢀ andꢀ

1152ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
(a)
C 1s
(b)
Pt 4f7/2
Pt 4f5/2
Pt(0)
Pt 4d
Pt 4p3/2
O 1s
Pt(II)
N 1s
Pt 4f
Pt(IV)
78
0
200
400
600
70
72
74
76
80
Binding energy (eV)
Binding energy (eV)
(c)
(d)
Pt 4f7/2
Pt 4f7/2
Pt 4f5/2
Pt 4f5/2
Pt(0)
Pt(0)
Pt(II)
Pt(IV)
Pt(II)
Pt(IV)
78
70
72
74
76
78
80
70
72
74
76
80
Binding energy (eV)
Binding energy (eV)
Fig.ꢀ3.ꢀBroadꢀscanꢀofꢀPt/hNCNCꢀ(a)ꢀandꢀPtꢀ4fꢀXPSꢀspectraꢀofꢀPt/hNCNCꢀ(b),ꢀPt/hCNCꢀ(c),ꢀandꢀPt/XC‐72ꢀ(d).ꢀ
(a)
-0.3
(b)
CO stripping
Background
-0.2
Pt/hNCNC
Pt/hCNC
0
.0
0.0
0.2
0.4
0.6
0.8
-
0.3
0.0
Pt/hNCNC
Pt/hCNC
Pt/XC-72
-0.3
Pt/XC-72
0.2
0.0
0
.0
0.4
0.6
0.8
1.0
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
Potential (V vs. Ag/AgCl)
Potential (V vs. Ag/AgCl)
Fig.ꢀ4.ꢀECSAꢀofꢀPt/hNCNC,ꢀPt/hCNCꢀandꢀPt/XC‐72.ꢀ(a)ꢀCVꢀcurvesꢀofꢀhydrogenꢀadsorptionꢀinꢀN
CVꢀcurvesꢀofꢀCOꢀstrippingꢀinꢀ0.5ꢀmol/LꢀH SO ꢀatꢀscanꢀrateꢀofꢀ20ꢀmV/s.ꢀ
2
‐saturatedꢀ0.5ꢀmol/LꢀH
2
SO ꢀatꢀscanꢀrateꢀofꢀ50ꢀmV/s;ꢀ(b)ꢀ
4
2
4
cantlyꢀ largerꢀ thanꢀ 242ꢀ mA/mgPt@0.64Vꢀ ofꢀ Pt/hCNCꢀ andꢀ 213ꢀ
mA/mgPt@0.65Vꢀ ofꢀ Pt/XC‐72,ꢀ inꢀ accordanceꢀ withꢀ theꢀ relativeꢀ
orderꢀofꢀtheirꢀECSAsꢀ(Fig.ꢀ5(a)).ꢀGenerally,ꢀtheꢀratioꢀofꢀtheꢀfor‐
superiorꢀtoꢀthatꢀofꢀPt/XC‐72.ꢀInꢀaddition,ꢀtheꢀchronoamperom‐
etryꢀ curvesꢀ ofꢀ Pt/hNCNCꢀ andꢀ Pt/hCNCꢀ presentedꢀ aꢀ relativelyꢀ
flatꢀ changingꢀ trend,ꢀ reflectingꢀ aꢀ higherꢀ stabilityꢀ thanꢀ thatꢀ ofꢀ
Pt/XC‐72ꢀ(Fig.ꢀ5(b)).ꢀ ꢀ
Theseꢀ resultsꢀ suggestedꢀ theꢀ hierarchicalꢀ carbon‐basedꢀ
nanocagesꢀwereꢀaꢀgoodꢀnewꢀsupportꢀdueꢀtoꢀtheꢀuniqueꢀnetworkꢀ
mesostructure.ꢀ Theyꢀ giveꢀ aꢀ highꢀ SSA,ꢀ goodꢀ conductivityꢀ andꢀ
rapidꢀ diffusion.ꢀ Nitrogenꢀ dopingꢀ canꢀ furtherꢀ regulateꢀ theꢀ ex‐
tendedꢀ andꢀ localꢀ electronicꢀ structureꢀ ofꢀ theꢀ carbonꢀ support,ꢀ
whichꢀfavorsꢀtheꢀhighꢀdispersionꢀofꢀtheꢀcatalyticallyꢀactiveꢀspe‐
wardꢀtoꢀbackwardꢀsweepingꢀpeakꢀcurrentꢀ(I
indexꢀtoꢀevaluateꢀtheꢀCOꢀtoleranceꢀorꢀtheꢀaccumulationꢀofꢀcar‐
bonaceousꢀ speciesꢀ forꢀ Pt‐basedꢀ catalysts.ꢀ Aꢀ higherꢀ I /I ꢀ indi‐
catesꢀlessꢀaccumulationꢀofꢀtheꢀcarbonaceousꢀspeciesꢀandꢀbetterꢀ
COꢀtoleranceꢀ[9,28].ꢀTheꢀI /I ꢀvaluesꢀwereꢀ1.09,ꢀ1.10ꢀandꢀ1.05ꢀ
f
/I
b
)ꢀisꢀusedꢀasꢀanꢀ
f
b
f
b
forꢀPt/hNCNC,ꢀPt/hCNCꢀandꢀPt/XC‐72,ꢀrespectively,ꢀindicatingꢀaꢀ
similarꢀ COꢀ toleranceꢀ ofꢀ Pt/hNCNCꢀ andꢀ Pt/hCNC,ꢀ whichꢀ wasꢀ

ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
1153ꢀ
(a)
Pt/hNCNC
Pt/hCNC
Pt/XC-72
(b)
-300
-300
-200
-100
0
Pt/hNCNC
Pt/hCNC
-
200
100
0
-
Pt/XC-72
0.2
0.4
0.6
0.8
1.0
0
500
1000
1500
2000
Potential (V vs. Ag/AgCl)
Time (s)
Fig.ꢀ5.ꢀCVꢀ(a)ꢀandꢀchronoamperometricꢀ(b)ꢀcurvesꢀforꢀPt/hNCNC,ꢀPt/hCNC,ꢀandꢀPt/XC‐72.ꢀ
ciesꢀtoꢀachieveꢀaꢀhighꢀactivityꢀ(Figs.ꢀ1,ꢀ4,ꢀandꢀ5).ꢀBasedꢀonꢀourꢀ
previousꢀstudy,ꢀfromꢀquarternaryꢀN‐doping,ꢀtheꢀextraꢀelectronsꢀ
occupyꢀtheꢀπ*ꢀorbitalꢀandꢀactivateꢀtheꢀneighboringꢀcarbonꢀat‐
oms,ꢀwhileꢀfromꢀpyridinicꢀN‐doping,ꢀtheꢀloneꢀpairꢀelectronsꢀfillꢀ
intoꢀ theꢀ p‐likeꢀ nonbondingꢀ orbitsꢀ [12].ꢀ Bothꢀ casesꢀ wouldꢀ en‐
hanceꢀtheꢀinteractionꢀbetweenꢀhNCNCꢀandꢀdꢀorbitalꢀofꢀPt,ꢀthusꢀ
facilitatingꢀtheꢀdispersionꢀofꢀPtꢀnanoparticlesꢀandꢀtheꢀelectro‐
catalyticꢀoxidationꢀofꢀmethanolꢀ[13–15].ꢀ ꢀ
ofꢀcatalystsꢀwithꢀhighꢀPtꢀloadingsꢀofꢀ30,ꢀ40ꢀandꢀ60ꢀwt%ꢀwereꢀ
preparedꢀ andꢀ characterizedꢀ asꢀ shownꢀ inꢀ Fig.ꢀ 6.ꢀ Evenꢀ forꢀ theꢀ
highꢀ loadingꢀ upꢀ toꢀ 60ꢀ wt%,ꢀ theꢀ Ptꢀ nanoparticlesꢀ canꢀ stillꢀ beꢀ
highlyꢀandꢀhomogenouslyꢀdispersedꢀonꢀhNCNCꢀwithoutꢀseriousꢀ
agglomeration,ꢀwithꢀtheꢀaverageꢀsizeꢀofꢀ5.5ꢀnm,ꢀwhichꢀwasꢀinꢀ
theꢀoptimumꢀparticleꢀsizeꢀrangeꢀofꢀ3–10ꢀnmꢀforꢀefficientꢀmeth‐
anolꢀelectrooxidationꢀ[29]ꢀ(Fig.ꢀ6(a)).ꢀDueꢀtoꢀtheꢀhighꢀaffinityꢀofꢀ
nitrogen,ꢀ nitrogenꢀ dopingꢀ convertsꢀ theꢀ nonpolarꢀ covalentꢀ
bondsꢀofꢀtheꢀcarbonꢀmatrixꢀintoꢀpolarꢀbonds,ꢀwhichꢀgeneratesꢀ
ByꢀmakingꢀuseꢀofꢀtheꢀuniqueꢀadvantagesꢀofꢀhNCNC,ꢀaꢀseriesꢀ
(b)
60 wt
(
a)
40 wt
0 wt
-100
3
-80
-60
-40
-20
0
20 wt
3
4
5
6
7
8
Particle size (nm)
20 nm
0.2
0.4
0.6
0.8
1.0
Potential (V vs. Ag/AgCl)
(c)
60 wt
(d)
-350
-
95
4
3
2
0 wt
0 wt
0 wt
-300
-200
-100
0
-
-
-
-
300
250
200
150
-90
85
-80
75
-
-
0.2
0.4
0.6
0.8
1.0
20
30
40
50
60
Potential (V vs. Ag/AgCl)
Pt loading (wt%)
Fig.ꢀ6.ꢀActivityꢀforꢀmethanolꢀoxidationꢀofꢀPt/NCNCꢀcatalystsꢀwithꢀPtꢀloadingꢀofꢀ20,ꢀ30,ꢀ40,ꢀandꢀ60ꢀwt%.ꢀ(a)ꢀTEMꢀimageꢀforꢀPtꢀloadingꢀofꢀ60ꢀwt%;ꢀInsetꢀisꢀ
theꢀparticleꢀsizeꢀhistogramꢀfromꢀ400ꢀPtꢀnanoparticles.ꢀ(b)ꢀCVꢀcurvesꢀnormalizedꢀbyꢀtheꢀtotalꢀmassꢀofꢀcatalyst;ꢀ(c)ꢀCVꢀcurvesꢀnormalizedꢀbyꢀPtꢀmassꢀ
only;ꢀ(d)ꢀPlotꢀofꢀforwardꢀsweepingꢀpeakꢀcurrentꢀvs.ꢀPtꢀloading.ꢀPeakꢀcurrentsꢀwereꢀnormalizedꢀbyꢀcatalystꢀmassꢀandꢀPtꢀmass,ꢀrespectively.ꢀ

1154ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
theꢀfunctionalꢀanchoringꢀsitesꢀbeneficialꢀforꢀtheꢀheavyꢀloadingꢀ
ofꢀ Pt.ꢀ Withꢀ increasingꢀ Ptꢀ loadingꢀ fromꢀ 21.6ꢀ toꢀ 60ꢀ wt%,ꢀ theꢀ
peak‐currentꢀ densityꢀ perꢀ unitꢀ massꢀ ofꢀ catalystꢀ graduallyꢀ in‐
creasedꢀfromꢀ73.7ꢀtoꢀ95.6ꢀmA/mgꢀbyꢀ30%,ꢀwhichꢀisꢀbeneficialꢀ
toꢀachievingꢀaꢀhighꢀpowerꢀdensityꢀ(Fig.ꢀ6(b)ꢀandꢀ(d)).ꢀHowever,ꢀ
theꢀcurrentꢀdensityꢀperꢀunitꢀmassꢀofꢀPtꢀspeciesꢀdecreasedꢀfromꢀ
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4.ꢀ ꢀ Conclusionsꢀ
2
hNCNCꢀwasꢀexploredꢀasꢀaꢀnewꢀsupportꢀforꢀPtꢀnanoparticles.ꢀ
[8] T.ꢀHyeon,ꢀS.ꢀHan,ꢀY.ꢀE.ꢀSung,ꢀK.ꢀW.ꢀPark,ꢀY.ꢀW.ꢀKim,ꢀAngew.ꢀChem.ꢀ
Int.ꢀEd.,ꢀ2003,ꢀ42,ꢀ4352–4356.ꢀ
TheꢀresultingꢀPt/hNCNCꢀcatalystꢀexhibitedꢀhighꢀelectrocatalyticꢀ
performanceꢀandꢀstabilityꢀforꢀmethanolꢀoxidation.ꢀTheꢀhierar‐
chicalꢀmesostructureꢀgaveꢀaꢀhighꢀaccessibleꢀsurfaceꢀarea,ꢀgoodꢀ
conductivity,ꢀ andꢀ rapidꢀ diffusion.ꢀ Nitrogenꢀ dopingꢀ furtherꢀ in‐
creasedꢀ theꢀ functionalꢀ anchoringꢀ sitesꢀ forꢀ Pt,ꢀ regulatedꢀ theꢀ
electronicꢀ structureꢀ ofꢀ theꢀ carbonꢀ matrix,ꢀ andꢀ enhancedꢀ theꢀ
interactionꢀbetweenꢀtheꢀsupportꢀandꢀmetalꢀcatalyst.ꢀAtꢀ20ꢀwt%ꢀ
loading,ꢀPtꢀnanoparticlesꢀwithꢀtheꢀsizesꢀofꢀ3.3ꢀnmꢀwereꢀevenlyꢀ
dispersedꢀ onꢀ hNCNCꢀ withoutꢀ aggregation,ꢀ whichꢀ wasꢀ betterꢀ
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9
[
1
[
12] H.ꢀFeng,ꢀJ.ꢀMa,ꢀZ.ꢀHu,ꢀJ.ꢀMater.ꢀChem.,ꢀ2010,ꢀ20,ꢀ1702–1708.ꢀ
13] B.ꢀYue,ꢀY.ꢀW.ꢀMa,ꢀH.ꢀS.ꢀTao,ꢀL.ꢀS.ꢀYu,ꢀG.ꢀQ.ꢀJian,ꢀX.ꢀZꢀWang.,ꢀX.ꢀS.ꢀWang,ꢀ
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[
thanꢀwithꢀtheꢀcontrolꢀsupportsꢀofꢀXC‐72ꢀandꢀhCNC.ꢀTheꢀECSA
H
ꢀ
[14] S.ꢀJ.ꢀJiang,ꢀY.ꢀW.ꢀMa,ꢀG.ꢀQ.ꢀJian,ꢀH.ꢀS.ꢀTao,ꢀX.ꢀZ.ꢀWang,ꢀY.ꢀN.ꢀFan,ꢀY.ꢀN.ꢀ
2
Lu,ꢀZ.ꢀHu,ꢀY.ꢀChen,ꢀAdv.ꢀMater.,ꢀ2009,ꢀ21,ꢀ4953–4956.ꢀ
andꢀ ECSACOꢀ ofꢀ Pt/hNCNCꢀ wereꢀ 45.6ꢀ andꢀ 51.8ꢀ m /gPt,ꢀ whichꢀ
wereꢀmuchꢀlargerꢀthanꢀthoseꢀofꢀPt/hCNCꢀandꢀPt/XC‐72,ꢀleadingꢀ
toꢀtheꢀbestꢀelectrocatalyticꢀperformanceꢀofꢀPt/hNCNC.ꢀInꢀaddi‐
tion,ꢀ hNCNCꢀ exhibitedꢀ aꢀ largeꢀ loadingꢀ capacityꢀ dueꢀ toꢀ theꢀ
uniqueꢀstructureꢀ andꢀabundantꢀnitrogenꢀ sites.ꢀ Smallꢀ Ptꢀnano‐
particlesꢀcanꢀbeꢀloadedꢀonꢀhNCNCꢀupꢀtoꢀ60ꢀwt%ꢀwithoutꢀseri‐
ousꢀ agglomeration,ꢀ andꢀ gaveꢀ higherꢀ catalyticꢀ currentsꢀ andꢀ
higherꢀpowerꢀdensity.ꢀTheꢀhierarchicalꢀmesostructureꢀandꢀni‐
trogenꢀ participationꢀ ofꢀ hNCNCꢀ canꢀ giveꢀ aꢀ generalꢀ electrodeꢀ
materialꢀforꢀenergyꢀconversionꢀandꢀstorage,ꢀe.g.,ꢀforꢀheteroge‐
neousꢀcatalysis,ꢀsupercapacitors,ꢀandꢀlithiumꢀairꢀbatteries.ꢀ
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[
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Acknowledgmentsꢀ ꢀ
Yang,ꢀ Z.ꢀ Jin,ꢀ Y.ꢀ W.ꢀ Ma,ꢀ J.ꢀ Liu,ꢀ Z.ꢀ Hu,ꢀ Adv.ꢀ Mater.,ꢀ 2015,ꢀ 27,ꢀ
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Theꢀ authorsꢀ acknowledgeꢀ theꢀ supportsꢀ fromꢀ Nanjingꢀ Uni‐
versity.ꢀX.ꢀF.ꢀJiangꢀwouldꢀlikeꢀtoꢀhighlyꢀthankꢀDrs.ꢀH.ꢀS.ꢀTao,ꢀS.ꢀJ.ꢀ
Jiang,ꢀX.ꢀT.ꢀQinꢀandꢀP.ꢀY.ꢀZangꢀforꢀtheirꢀvaluableꢀassistancesꢀandꢀ
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[
GraphicalꢀAbstractꢀ
Chin.ꢀJ.ꢀCatal.,ꢀ2016,ꢀ37:ꢀ1149–1155ꢀ ꢀ ꢀ doi:ꢀ10.1016/S1872‐2067(15)61117‐2
High‐performanceꢀPtꢀcatalystsꢀsupportedꢀonꢀhierarchicalꢀ ꢀ
nitrogen‐dopedꢀcarbonꢀnanocagesꢀforꢀmethanolꢀ ꢀ
electrooxidationꢀ
XiangfenꢀJiang,ꢀXuebinꢀWang,ꢀLimingꢀShen,ꢀQiangꢀWu,ꢀ ꢀ
YangnianꢀWang,ꢀYanwenꢀMa,ꢀXizhangꢀWang*,ꢀZhengꢀHu*ꢀ
NanjingꢀUniversity,ꢀChina;ꢀ ꢀ
ꢀ
ꢀ
NationalꢀInstituteꢀforꢀMaterialsꢀScienceꢀ(NIMS),ꢀJapanꢀ
Ptꢀnanoparticlesꢀwereꢀhighlyꢀdispersedꢀonꢀaꢀnewꢀcatalystꢀsupportꢀ
ofꢀ hNCNC,ꢀ andꢀ gaveꢀ highꢀ activityꢀ forꢀ methanolꢀ oxidationꢀ dueꢀ toꢀ
nitrogenꢀparticipationꢀandꢀtheꢀuniqueꢀfeaturesꢀofꢀhNCNC.ꢀ
hNCNC
Pt/hNCNC

ꢀ
XiangfenꢀJiangꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ1149–1155ꢀ
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