The Use of Electroless Plating Deposition to Prepare

Pd/y-AI203 Nanofiber CatalystWeimin Kang, Quanxiang Li, Bowen Cheng, Yuanlin Ren, and Xupin Zhuang

Abstract-Gamma-alumina (y-Ah03) nanofibres with 300­1500 nm diameter have been prepared by calcination ofanhydrous aluminium chloride/polyvinylpyrrolidone(AICIPVP) hybrid fibres about 5 h at 900°C which wereprepared by electrospinning as precursor. Nano Palladium(Pd) particles were deposited by electroless platingdeposition (EPD) onto y-Alz03 nanofibre surfaces to formPd/y-Ah03 nanofibre (PANF) catalyst for the first time.The surface morphology and functional group andelemental concentrations of the Pd/y-Ah03 nanofibreCatalyst were examined by SEM, XRD and XPS. Theresults showed that nano Pd particles round 70-150 nm indiameter were uniformly distributed on the y-Ah03nanofibre surfaces.

BACKGROUND

Alumina (Ah03) has long been attracting broad interestsdue to their high strength and elastic modulus, corrosionresistance, low thermal conductivity, chemical stableness andgood electrical insulation. [I] Ah03 can exists in a large varietyof crystallographic forms , such as u , y, e, 8, and so on.Among all of them, y-Ah03' because of its huge surface area tovolume ratio, is often used as adsorbents, catalysts and catalystsupports and etc, especially in nanoscale.Pr'' Electrospinning isa process using high static voltages to produce aninterconnected nonwoven web of fine fibers with diameter inthe range of 50-5000 nm, which has been found to be uniqueand cost effective for fabricating nonwoven with large surfacearea. [4,5\ Electroless plating depositon (EPD) is a non-galvanictype of plating method that deposits the anticipated films onsubstrates by the autocatalytic reaction of the coated materialswithout the use of external electrical power.[6\ The objective ofthe present in vitro study is to anchor nano Pd particles onto y­AI203 nanofibre surfaces by electroless palladium plating at70 'C for 40min to prepare PANF catalyst.

CURRENT RESULTS

Micrographs of electrospun AICbIPVP hybrid fibers wereshown in Fig. I(a). It can be seen that the diameter of thehybrid fibers is in the range of about I~6 micrometers. Fig. I(b) shows the micrographs ofy-Ah03nanofibres by calcinationof the hybrid fibres about 5 h at 900 °C, whose diameter dropsdown into the ranges of 300 to 1500 nm. Fig. I(c) and (d)shows the SEM images of the PANF catalyst. It can be seen

All authors are with Tianjin Municipal Key Lab of Fiber Modification andFunctional Fiber, Tianjin Polytechni c University, Tianjin, China, 300160(*Contacting Author: Phone : +86+22+24528018; bowen63@\ 26.com)

978-1-4244-3544-9/10/$25 .00 ©2010 IEEE

clearly that lots of nano Pd particles round 70~ 150 nm indiameter were uniformly distributed on the y-Ah03 nanofibresurfaces.

Fig. I. SEM of PVP/AICb hybrid fibers (a), alumina nanofibers (b), PANF catalyst(c) and enlarged PANF catalyst(d).

Fig.2 shows the FTIR spectra of the PVP/AICb hybridfibers and y-Ah03 nanofibre. It can be seen clearly that twostrong bands appear around 3000cm·1 and 1600cm'] in Fig.2(a) ,which can be assigned to the bending and stretchingvibration of C-H and C=O groups of PVP, respectively. FromFig.2 (b), we can see that the band in the region of 500~ 1000cm- I corresponding to AI-0 bond and the two bands at 1600and 3000cm'] in the spectrum of the PVP/AICb hybrid fibersdisappear.

(b)

C-H

4000 3500 3000 2500 2000 1500 1000

Wavenumber (ern")

Fig.2 FTIR spectrum for PVP/AICI3 hybrid fibers (a) andalumina nanofibers (b).

0 1,

Fig. 3 XRD spectra for the alumina fibers(a) and PANFcatalyst(b).

Fig.6 High-resoluion XPS spectra ofPd3d3 and Pd3d5

ACKNOWLEDGMENT

328 330 332 334 336 338 340 342 344 346 348

Binding Ener gy (eV)

1000

2000

~,

~ 3000oU

4000

Fig.5 High-resoluion XPS spectra of Alzp of y-Alz0 3

nanofibre(a) and PANF catalyst (b).

5000

64 66 68 70 72 74 76 78 80 82 84 86

Bin ding Energy (eV)

( 111 )

lA Jl20 30 40 50 60 70

20 (' )

a

15 20 25 30 35 40 45 50 55 60 65 70 I 1029n

As shown in Fig. 3(a), there are seven reflection peakscentering at 2e of 19°(111),32°(220),37°(311),39°(222),46°(400), 6JO(511), 67°(440), respectively, whichcould be exactly indexed as pure y-alumina. While in the XRDpattern of the Pd/v-Al-O, nanofibre Catalyst shown in Fig.3(b),there are three reflection peaks centering at 2e of 40.5°(111),46.8°(200) and 6804°(220) corresponding to pure palladium,which also shows that the y-Alz03 nanofibre was basicallycovered by Pd particles.

Fig.a shows the XPS spectra of y-Alz03 nanofibre andPANF catalyst. It can be seen that in the whole region there aretwo peaks of Pd3d3 and Pd3d5 in the PANF catalyst sample inaddition to the peaks of Alzp, CIs and Oj, presented in the y­Alz03 nanofibre (Figo4(a)), and the Alzp of the PANF catalystwas decreased to 1.63 at.% from the original 31.49 at.% of they-Alz03 nanofibre sample.

200 400 600 800 1000 1200 1400

Binding Energy (eV)

Fig.d. the XPS spectra of y-Alz03 nanofibre(a) and PANFcatalyst(b)

As shown in Fig.5, the peaks at the binding energies of74042 eV correspond to Alzp• The peak of Alzp shows only onesymmetric component and has no shoulder peak, whichillustrates that the aluminum-containing compound is Alz03•

The characteristic peaks at the binding energies of335.0eV and340.3eV correspond to Pd3d3 and Pd3d5 of pure palladium (33.7at.%) respectively (Fig. 6).

This work was supported by the National ScienceFoundation ofTianjin, China. (No. 06YFJMJC02600)

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