Nghien cifu - Trao do!
Nghien cuU va tong hofp hofp kim xuc tac nano ptrumo/c trong pin nhien lieu mpt dang nang liTtfng sach trong tiTofng lai
O NGUYEN THUY T a d N G VI Trudng D^i hgc Bich khoa TP. Hd Chi Minh
H 6 T H ( THANH V A N
TrUdng Dal hgc Tii nguyen va Mil trudng TP. H6 Chl Minh
H
pp kim xOc tic hgt nano PtRuMo/C dupe tong hpp bang phuang phip khd hda hgc d nhigt dg thap td cic mudi tUdng dng vdi chit khd li Sodium borohydride (NABH4).Bing phuang phap do nhiiu xg (XRD), kinh hiin vidign td truyen qua (TEM), phd tan xg nang lupng tia X (EDX) dexic dinh kha nang anh hudng cua Pt trong hpp kim xOc tic hgt nano PtRuMo/C.
Dat v a n d l
Pt + C H 3 0 H -* Pt-CO + 4 H + + 4e- (1)
M + H 2 0 -* Ru-OH + 4 H + + e- (2)
Pt-CO + M-OH -* Pt + M + C 0 2 + H+ + e- (3)
Trong p h g m vi bdi b a o ndy, chung toi tien hanh tong hgp hgp kim xue tae nano PtRuMo/C bang phuong phap khCf h d a hgc vdi ehdt khCf dugc s i i dung la Sodium borohydride ( N a B H 4 ) . T i l n hanh so sanh hogt tfnh xue tdc va khd ndng gidm ddu dgc xQe tdc P t R u M o ( 3 : 1 : 1 ) / C v a P t / C .
Nguydn lieu va phUOng phap t h y c n g h i g m
Nguyen ligu
T h a n Vulean-XC72R (Fuel Cell store), Ruthenium(lll) chlo-
ride hydrate (RUCI3.XH2O), A m -
monium molybdate tetrahydrate ( ( N H 4 ) 6 M 0 7 0 2 4 . 4 H 2 0 ) (Acres).
Sodium borohydride ( N a B H 4 ) , Nitric acid {HNO3, 6 5 - 6 8 % , Sulfu- ric acid (H2SO4, 9 5 - 9 8 % ) , ISO propyl alcohol {Trung Q u I e ) , nUdc eat.
Xd Ij^ than XC-72R Ckn 0.5g Carbon Vulcan X C - 72R eho vao mgt binh eau ba co chUa 500ml d u n g dich axit nitric (HNO3 5%). Hon hgp dugc khuay tQ va dun fi nhigt d6 105°C trong 16 gifi. sau khi dun x o n g , Idm ngugl b i n hgp va ly tam vdi v a n t i e 4500rpm trong 10 phut. Qua trinh ly tam dUde lap lai thgm 3 Idn vdi 2 ldn la nude cdt v d 1 lan ace- ton. Sau d d , lay p h d n ran say t r o n g 4 g i 0 6 l 2 0 ' ' C .
Tdng hpp xOc tic PtRuMo/C Cho 2 5 m g carbon V u l c a n X C - 7 2 R da xit ly v d o becher chQa 10mi nude cat vd 2 m l dung dieh iso propyl ancol. H i n h g p dugc ddnh sieu g m trong 20 phut de giup cho qua trinh trgn lan dugc dong d i u , . Sau do cho tien chat axit Choioroplatinie, muoi RUCI3.XH2O va m u o i { N H 4 ) 6 M07O4.4H2O duge eho v d o hdn hgp, tiep tye danh sieu d m trong 15 p h u t Chinh pH m d i t r u d n g cua h i n hgp bang NaOH 1M Idn d i n 9 va ndng ngay nhiet do h i n
h g p ldn 80°C trudc khi nhd tQng gigt N a B H 4 0.2M v d o vd khuly trong 1 gid. D e ngugi va ly tdm d mQc 4500 rpm trong 10 phut. Qua trinh ly tdm dugc t i l n hdnh gilng n h u q u a trinh xCf ly than Vulcan X C - 7 2 R . San p h a m r l n duye say 6 l 2 0 ° C t r o n g 3 g i d .
Thiet biphan tich Kfnh h i l n vi dien t i i truyen q u a T E M , J E M - 1400 (Nhdt).
May n h i l u x g tia X BRUKER X R D -D8 A D V A N C E (DQc). Pho tan xa n a n g lugng tia X (EDX), Quet t h l v d n g tuan hoan.
K e t q u d va t h d o l u | n K e t q u d p h a n t f c h XRD Q u a n sat pho n h i l u xg cua cac m l u ta thay ehung d i u co ede m u i nhieu xa b eac gdc 29 = 39.6, 4 7 . 4 , 6 7 . 1 " , ede gdc nay hodn t o d n phu hop vdi eac mdt (111), (200), (220) cua cdu tnic lap phUdng tdm mdt (fee) ciia platinum (Pt) da dugc cong b l trong t h u vign p h i , k i t qud ndy c d the chUng to duge s y hidn didn c u a eac tinh t h l Platinum trong eac mSu xuc tae da t i n g hgp. Ngoai ra, trdn hinh cdn x u l t hign mdt mui nhieu xa 6 29 « 25°, goc nay tUdng Qng vdi mdt (002) trong eau true lue giae eua c a c b o n (Vulcan XC-72R.TU dO lieu phdn tfch X R D c^a cac m l u
2 8 Toi n g u y e n v g M6I t r u o n g [ K^l-Th^ng 6/2016
ta cdn CO t h l udc tfnh kfeh thude trung binh eCia cdc hgt xiic tde Pt bang cdng thUe Seherrer tQ mat (111).
Lcose
Trong dd, L: kich thudc trung binh ciia tinh the hgt Pt, B:
FWHM, K: Hang so Seherrer, phy thugc vao do rdng dUde xae djnh nhu the nao, hinh dgng tinh t h l , sy phdn bo kfeh thude tinh t h l , X: budc sdng cua bUc xg dugc sCr dung de thu thdp dD lieu.Kich thudc trung binh mau xuc tae PtRuMo/C (3:1:1) duge Ude tfnh bang edng thUc Seherrer colklchi thude khodng 4.22 nm.
Kit qua phan tich do TEM Qua hinh TEM cho thdy, cac hat xuc tac phan bo kha dong d i u , phan mau nhgt hdn Id chat mang carbon XC-72R, phan mdu dam hdn chfnh hdp kim PtRuMo.
Ben cgnh do, tQ hinh TEM cQa cde mdu, chung ta cd the Ude tfnh duge kfeh thudc trung binh ciia cdchgtxuctdcPtRuMo/C euaca 2 mau xue tac PtRuMo/C (3:1:1) khodng 4-5 nm, dilu ndy eho thdy su tUdng dong ve kich thUdc giDa kit qud do TEM va k i t qua tfnh toan tu XRD.
Kdt qua phan tich do EDX De xae dinh ty Id nguydn tii giDa cde kim logi cd trong hgp kim xue tde Pt, Ru vd Mo ta tiln hdnh tiln hdnh kiem tra bang phUdng
Bang 1. Bing thinh phan
phan tram khdi luang cua PtRuMo/C (3:1:1) Phi chup EDX
cua PtRuMo/C (3:1:1)
PtRuMo/C (3.1:1)
Thaih phan phdn tram khoi luvng
Pi 62 8
Ru 21.19
Mo 16.01
phdp do EDX. K i t qua do dugc trinh bay fi bang sau:
Kit qua do dign hda (CV) TU cac dudng eong CV , Chung ta ed t h l tinh dien tieh b l mat hogt hoa ridng eCia cde hgt xue tdc PtRuMo/C va Pt/C bang each lay tich phan eua phan gidi hdp hydrogen va tfnh theo cdng thUe sau:
S QH ^ | K / i ( E ) d £ ESA-H ( P t ] x 0 „ ^ „ , a y „ (Pt]x0.2I
Trong dd, SESA-H Id dien ti'ch be mat boat hda rieng cua Pt (m^/g ), O H la dien tfch eho sU gidi hdp hydrogen (mC.cm'^), 0.211a Qmonolayer,(fnCcm-^) (dien tfch lien quan d i n hap phu hogc gidi hap ciia mgt idp hydro- gen tren mgt b l mat Pt da tinh thl), V Idtd'edg quet t h l (mV.s"
') va [Pt] la lugng Pt tren didn eye (mg hoge mg.em-^). Kit qud tfnh ESA dugc thu ggn trong bang 2.
Bang 2. Bang diin tich tye mat