Article http://sciencetechindonesia.com Article History Received: 21 November 2016 Received in revised form: 22 January 2017 Accepted: 3 February 2017 DOI: 10.26554/sti.2017.2.2.50-55 ©2017 Published under the term of the CC BY NC SA license Science & Technology Indonesia p-ISSN: 2580-4405 e-ISSN: 2580-4391 Sci. Technol. Indonesia 2 (2017) 50-55 SYNTHESIS AND CHARACTERIZATION OF METAL OXIDES SUPPORTED KEGGIN TYPE POLYOXOMETALATE Rb2K2[γ-H2SiV2W10O40].nH2O Eiffel Ostan Jeski Gultom1*, Aldes Lesbani1 1Department of Chemistry, Faculty of Mathematic and Natural Sciences, Sriwijaya University *Corresponding Author Email: eiffelgultom@gmail.com ABSTRACT Synthesis of material based on polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O with SiO 2 , TiO 2 , ZrOCl 2 , and TaCl 5 was carried out to form Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-SiO 2 , Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-TiO 2 Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-ZrOCl 2 and Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-TaCl 5 . Materials from preparation were characterized through functional group analysis using FT-IR spectrophotometer, crystallinity analysis using XRD and surface photograph analysis using SEM. The results show that material Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O was successfully loaded with SiO 2 , ZrOCl 2 and TaCl 5. Based on SEM photo Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O- TiO 2 and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-ZrOCl 2 were the best material from preparation base on the homogeneity particle distribution. The FT-IR spectrum shows specific wavenumber for nanomaterial Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-TiO 2 in the range 455-910 cm-1 and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O - ZrOCl 2 in the range 393.48-1404 cm-1. XRD pattern for material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-TiO 2 and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-ZrOCl 2 show there is a difference between polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O, TiO 2 and ZrOCl 2. SEM photo analysis of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-TiO 2 and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O-ZrOCl 2 showed that material polyoxometalate with support has a diameter size of particle above 100 nm. Keywords: Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O, polyoxometalate, SiO 2 , TaCl 5 , TiO 2 , ZrOCl 2 . INTRODUCTION Synthesis, modification, and preparation of inorganic material are still developed until this year. Various inorganic materials such as metal oxides (Wang et.al, 2017), zeolites (Dehghan and Anbia, 2017), layer materials (Hanifa and Palapa, 2016), inorganic com- plexes (Ramdass et.al, 2017), organometallic compounds (Pettinari, et.al, 2016) are widely used in many aspects of our life. These ma- terials are also essential for an industrial processes such as catalysts, ion exchanges, membranes, adsorbents, and sensors. Among these materials, inorganic cluster such as polyoxometalates compounds is another class of unique and specific material due to the acid base and redox properties (Genovese and Lian, 2017). Polyoxometalates are metal-oxygen inorganic clusters with high adicity properties, redox properties, and high solubility due to the flexibility of met- al exchange of heteroatom and addenda atom. Polyoxometalates have several structures such as Keggin, Dawson, Anderson, and also Lacunary polyoxometalates (Gao et.al, 2017). On the other hand, this material is important for industrial catalysis and has been applied in industrial organic synthesis and transformation of var- ious functional groups. Thus the development of this material is still developed until this decade. The developing of polyoxometalates can be reached by ad- denda/heteroatom metal exchange to form novel polyoxometa- lates or modification such as grafting (Yong et.al, 2016), sol-gel (Tambunan and Mohadi, 2017), or impregnation by other metal oxides (Dizaji et.al, 2017). The aim of these research is to obtain polyoxometalates with high acidity properties, high surface area, and low morphology size. Thus application as a catalyst for many organic reactions can be facile. Metal oxides were used as support for polyoxometalate in order to obtain high surface area and low morphology properties such as titanium, silica, and alumina. This modification method is an easy and simple way to get advantage properties of polyoxometalates. In this research, various metal oxides such as silica, titanium, zirconium, and tantalum have been used as a support of poly- oxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. Polyoxometalate Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O is vanadium substituted Keggin type polyoxometalate. We expected that modification of this polyoxo- metalate could obtain unique properties of this material. Polyoxo- metalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O supported silica, titanium, zirconium, and tantalum was characterized using FTIR spectrosco- py, powder X-Ray analysis and identification of surface morphol- ogy by SEM. EXPERIMENTAL SECTION Materials and Equipment Chemicals were used in this research from Merck and Sigma Al- drich such as sodium metasilicate, sodium tungstate, hydrochloric acid, potassium chloride, potassium carbonate, sodium metavana- date, rubidium chloride, cyclohexane, acetone, etanol, ammonia, silica dioxide, titanium dioxide, zirconium oxo chloride, and tanta- lum pentachloride. FTIR spectrum was recorded using Shimadzu FTIR Pres- tige-21 using KBr pellet and scanning wavenumber from 300-4000 cm-1. XRD powder pattern was obtained from Shimadzu LabX type-6000 with scanning speed one deg.min-1. SEM photograph was obtained from SEM Jeol JED-2300. Gultom et al. 2017/Science & Technology Indonesia 2 (2) 2017:50-55 © 2017 Published under the term of the CC BY NC SA 4.0 licence 51 Synthesis Rb2K2[γ-H2SiV2W10O40].nH2O (Nakagawa et.al, 2005) Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O was synthesis from K 8 [β 2 -SiW 11 O 39 ]14H 2 O. Sodium metavanadate 0.5 M was ob- tained by dissolving sodium meta vanadate in hot water (solution A). Polyoxometalate K 8 [β 2 -SiW 11 O 39 ]14H 2 O (10 g) was mixed with 35 mL of hydrochloric acid 1M (solution B). Solution A was add- ed quickly to solution B with gentle stirring and the solution to be yellow. Into these solutions, rubidium chloride (5) was added, and the solution was mixed for 15 minutes to form yellow crystals. Yellow crystals were vacuum filtered. The crystals were dissolved in water, and remaining crystals were removed by filtration. The solution was vacuum concentrated to form yellow crystals of Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. Characterization was conducted using FTIR, XRD, and SEM analyses. Preparation of Rb2K2[γ-H2SiV2W10O40].nH2O/SiO2 (Kim et.al, 2006) Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (1g) was dis- solved with 50 mL methanol. Silica dioxide (2.5 g, 24o mesh) was added into polyoxometalate solution and solution was stirred for 30 minutes. The solution was kept for 24 hours and concentrated by vacuum. The solid material was washed with acetone and dried at 110 oC. Preparation of Rb2K2[γ-H2SiV2W10O40].nH2O/TiO2 (Pozniczek et al. 2006) Preparation of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TiO 2 was carried out with slight modification from Pozniczek. Titanium oxide (1 g) was mixed with ethanol (50 mL) and into the solution was added Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (1g). The solution was heated at 50 oC for 45 minutes. The solid material was formed after cooling solution and was washed with acetone. Material was dried at 110 oC for 24 hours to form Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TiO 2 Preparation of Rb2K2[γ-H2SiV2W10O40].nH2O/ZrOCl2 (Devassy et al. 2002) Procedure for preparation of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ ZrOCl 2 was adopted from Devassy and was modified as follow. Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (1g) was dissolved in methanol (10 mL) (solution A). Zirconium oxo chloride (2.5 g) was mixed with ammonia (10 mL) (solution B). Solution A was mixed with solution B with slowly stirring at 50 oC for 15 minutes. The solution was centrifuged at 15,000 rpm for 5 minutes to form the solid material of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ZrOCl 2 . Ma- teri Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TaCl 5 al was washed with ace- tone and dried at 110 oC for 24 hours. Preparation of Rb2K2[γ-H2SiV2W10O40].nH2O/TaCl5 (Xu et al. 2008) Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (0.5 g) was dis- solved in ethanol (4 mL) and water (2 mL) was added into these solutions (solution A). Tantalum pentachloride (0.6 g) was mixed with ethanol (5 mL) (solution B). Solution B was mixed with solution A with slowly stirring for 1 hour. The solution was kept for 30 oC overnight to form gel. Gel was heated at 130 oC for 1 hour to form a solid material of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ TaCl 5 . The material was kept at 110 oC overnight to obtain Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TaCl 5 . Characterization of metal oxides supported Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. Characterization of metal oxides sup- ported polyoxometalate was carried out using the identification of functional groups by FTIR, X-Ray powder analysis, and surface morphology analysis by SEM. RESULTS AND DISCUSSION Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O was synthe- sized from polyoxometalates K 8 [β 2 -SiW 11 O 39 ].14H 2 O and K 8 [γ-Si- W 11 O 39 ].14H 2 O, thus comparison of FTIR spectrum of these compounds is needed as shown in Figure 1. Figure 1 shows FTIR spectrum of K 8 [β 2 -SiW 11 O 39 ].14H 2 O (A), K 8 [γ-SiW 11 O 39 ].14H 2 O (B) and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (C). All these Keggin type polyoxometalates have a similar vibration at wavenumber in the range 700-1100 cm-1. The main vibration of these polyoxometa- late is Si-O (at 700-720 cm-1), W-Oc-W and W-Oe-W (at 800-880 cm-1), and W=O (at 900-920 cm-1) (Nakagawa and Mizuno, 2007). Wavenumber at 3300 cm-1 is appeared in all FTIR spectra in Figure 1 due to water content. There are no significant changes in vibra- tion of these three polyoxometalates. Thus polyoxometalate Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O is characterized using X-ray analysis. Polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O were analyzed using X-ray analysis as shown in Figure 2. There are sharp dif- fraction peaks at 2θ value 26 deg, and 28 deg, which is contributed from crystalline substituted Keggin polyoxometalate. Furthermore, polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O was identified by SEM to know the morphology of these compound as shown in Figure 3. Figure 3 showed that polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O has a uniform with block shape. The particle size of Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O can be determined from Figure 3. The results show compound Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O has particle size distribution 1000 nm. This results indicated that Figure 1. FTIR spectrum of K 8 [β 2 -SiW 11 O 39 ].14H 2 O (A), K 8 [γ-Si- W 11 O 39 ].14H 2 O (B) and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (C). Figure 2. XRD powder pattern of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. Gultom et al. 2017/Science & Technology Indonesia 2 (2) 2017:50-55 © 2017 Published under the term of the CC BY NC SA 4.0 licence 52 compound Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O is needed to support with a metal oxide. Metal oxides such as silica, titanium, zirconi- um, and also tantalum chloride will be used as a support of Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. In the first experiment, silica dioxide was used as a support of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O and the materials were character- ized using FTIR analysis as shown in Figure 4. Figure 4C showed that polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O/SiO 2 has broaden peaks in the wavenumber range 600-1000 cm-1, which is attributed from a support agent. Although FTIR spectrum of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/SiO 2 was broaden but vibration of W-Oc-W and W-Oe-W is still appeared around 900-1000 cm-1. That vibrations are clue for silica oxide successfully supported polyoxometalate. Further characterization was conduct- ed using XRD and powder diffractogram is presented in Figure 5. Diffraction of material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/SiO 2 as shown in Figure 5C has different with both Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O and SiO 2 as starting materials. Diffraction appeared at 18 deg, 21 deg, 24 deg, and 28 deg. Peaks at 18 deg and 21 deg are probably come from silica and 24 deg, and 28 deg comes from poly- oxometalate, which was shifted to lower diffraction. This results in- dicated increasing crystallinity of material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O/SiO 2 . Thus novel properties of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/SiO 2 is expected. Further characterization was conducted using SEM. The results identification of morphology using SEM is shown in Figure 6. Figure 6 showed that material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ SiO 2 has uniform shape, but small aggregation appeared. Calcula- tion of particle size revealed that material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O/SiO 2 has particle size 2200 nm, which was higher than Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. For comparison of silica ox- ide as support thus titanium oxide was used as support for Rb- Figure 3. SEM photograph of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O. Figure 4. FTIR spectrum of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), SiO 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/SiO 2 (C). Figure 5. XRD powder pattens of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), SiO 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/SiO 2 (C). Figure 6. SEM photograph of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ SiO 2 Figure 7. FTIR spectrum of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), TiO 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 . Gultom et al. 2017/Science & Technology Indonesia 2 (2) 2017:50-55 © 2017 Published under the term of the CC BY NC SA 4.0 licence 53 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O to form Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O/TiO 2 . Spectrum FTIR material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 is presented in Figure 7. FTIR spectrum in Figure 7C for material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O/TiO 2 looks similar with spectrum FTIR for Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/SiO 2 in Figure 4c. Wavenumber at 700-1000 cm-1 was broad probably due to the interaction of metal oxides both silica and titanium. The vibration of polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/SiO 2 also appeared at wavenumber in the range 900-1000 cm-1, which was attributed to W-Oc-W and W-Oe-W vibrations. Further characterization using XRD toward Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 is shown in Figure 8. Figure 8 showed XRD powder pattern of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ]. nH 2 O (A), TiO 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TiO 2 (C). Diffraction of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 as shown in Figure 8C has the main diffraction in the range of 20-30 deg, which was attributed to Titania and polyoxometalate. Another dif- fraction also appeared at 35-48, 52-57, and 62 deg. This pattern is quite different with silica as support. Probably titanium oxide was dispersed on the surface of polyoxometalate. To know this phe- nomenon then SEM analysis was conducted and the SEM image of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 is shown in Figure 9. SEM photograph in Figure 9 showed although uniform shape appeared, but small aggregation was formed. Calculation of particle size resulted in the size particle 660 nm, which was smaller than polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/SiO 2 . Titanium and silica have dif- ferent properties thus the results of support material was also dif- ferent properties. To know the support properties thus experiment was conducted using zirconium. This experiment used zirconium oxychloride. This support quite different with silica and titanium due to chloride atom include in the support structures. The char- acterization for compound Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ZrOCl 2 and starting materials is presented in Figure 10. The interesting results were found that although zirconium dif- ferent with silica and titanium but FTIR spectrum is similar to all support in which peaks at wavenumber 700-1000 cm-1 is broad. The properties of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ZrOCl 2 is then explored through XRD powder pattern as shown in Figure 11. The results of XRD powder pattern as shown in Figure 11C for Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ZrOCl 2 indicated that that material has high crystallinity than silica and titanium as support. There are diffraction peaks at several areas i.e. less than 10 deg, 15-18 deg, and 25-33 deg. Diffraction of zirconium and polyoxometalate was overlapped. Diffraction at 8 deg is new diffraction which was prob- ably due to oxide and chloride interaction with polyoxometalate, and this diffraction is not found for silica or titanium as supports. Characterization using SEM for material Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/ZrOCl 2 as shown in Figure 12 is also interesting due to equal portion aggregation and uniform shapes. Particle size calculation showed that material Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ZrOCl 2 has particle size 220 nm. This particle size is widely different with polyoxometalate and other supports. To investigate the difference between pure oxides (silica and titanium), mixture oxide (zirconium), thus no oxide was used as support. Tantalum chloride was used as support for polyoxome- talate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O and analysis of FTIR toward Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TaCl 5 is shown in Figure 13. FTIR spectrum of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TaCl 5 (B) in Figure 13 showed that similar results were found between oxide, mixture oxide and non-oxide. Wavenumber at 700-1000 cm-1 was broad similar with the use of silica, titanium, and zirconium as supports. Further characterization using XRD and the pattern is shown in Figure 14. Diffraction of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TaCl 5 revealed that there was a sharp peak at diffraction 26 deg and broad peaks at 8-12 deg. This results indicated the use of metal chloride sup- port could create a material with different properties than oxide or mixture oxide supports. Identification using SEM to material Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/TaCl 5 as shown in Figure 15 resulted in particle size 330 nm. This size is smaller than polyoxometalate Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O. Thus all experiment shows the dif- Figure 8. XRD powder patten of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), TiO 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/TiO 2 (C). Figure 9. SEM photograph of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O/ TiO 2 . Figure 10. FTIR spectrum of Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O (A), ZrOCl 2 (B), and Rb 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ] .nH 2 O/ZrOCl 2 . Gultom et al. 2017/Science & Technology Indonesia 2 (2) 2017:50-55 © 2017 Published under the term of the CC BY NC SA 4.0 licence 54 ferent type of supports can create material with unique chemical and physical properties CONCLUSION Metal oxides supported polyoxometalate Rb- 2 K 2 [γ-H 2 SiV 2 W 10 O 40 ].nH 2 O were successfully conducted using TiO 2 , ZrOCl 2 , TaCl 5 dan SiO 2 . The various form and sizes were obtained on supported polyoxometalate with size distribution par- ticles more than 100 nm. ACKNOWLEDGEMENT We thanks to Kemenristekdikti Republik Indonesia for sup- porting this research through” Hibah Kompetensi“ 2015-2016. REFERENCES Dehghan. R., Anbia. M. (2017). Zeolites For Adsorptive Desul- furization From Fuels: A Review. Fuel Processing Technology, 167, 99-116. Devassy. B.M, Halligudi. S.B, Hedge. S.G, Halgeri. A.B, Lafebvre. F. (2002). 12-Tungstophosphoric Acid/Zirconia-A Highly Ac- tive Stable Solid Acid-Comparison With A Tungstated Zirconia Catalyst. 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