RESEARCH SCHOLARS’ MEET

ON 28TH March 2015

ABSTRACTS OF THE PRESENTATIONS

NATIONAL CENTRE FOR CATALYSIS RESEARCH

INDIAN INSTITUTE OF TECHNOLOGY MADRAS

CHENNAI 600 036

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PROGRAMME

1. A Soft-chemical approach for the synthesis Mo- Ni supported on Al-SBA-15 for hydrodenitrogenation of 2-propyl aniline, P. Santhana Krishnan, K. Shanthi, Department of Chemistry, Anna University, Chennai – 25. [8.30-8.50A.M.]

2. Mesoporous SBA-15 supported Rhenium catalysts for Hydrodenitrogenation of MCHA I. Effect of Re loading, K.Sureshkumara, S.J.Sardhar Bashaa and K.Shanthi, a Department of Chemistry, Anna University, University College of Engineering, Ramanathapuram-623513, b

Department of Chemistry, Anna University, Chennai – 25. [8.50-9.10 A.M.]

3. Selective oxidation of adamantane over graphene supported CeO2 nanoparticles, A. Selvamaniand K. Shanthi, Department of Chemistry, Anna University, Chennai 600025, India. [9.10-9.30 A.M.]

4. M-TUD-1 as solid acid catalyst for one pot multicomponent synthesis of 1,4-Dihydropyridine derivatives, Department of Chemistry, Anna University, Chennai 600025, [9.30-9.50 A.M.]

5. Cu-Mn-TUD-1: A Bimetallic Catalyst for Ethyl benzene Oxidation, [9.50-10.10 A.M.]

6. HYDRGENOLYSIS OF BIO-MASS DERIVED POLYOLS TO VALUE ADDED CHEMICALS, R. Vijaya Shanthi , S. Sivasanker, NCCR, Department of Chemistry, IIT- Madras, Chennai. [10.10-10.30 A.M]

7. Mesoporous silica-templated synthesis of ordered mesoporous copper oxide, V. R. Mohan and P. Selvam, National Centre for Catalysis Research and Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036 [11.00 TO 11.20 P.M.]

8. Mesoporous LiMPO4 (M = Fe or Mn) - Carbon Composites: Synthesis and Characterization, Sourav Khan and Parasuraman Selvam, National Centre for Catalysis Research, Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036. [11.20 TO 11.40 A.M.]

9. Influence of basicity on photo catalytic reduction of carbon dioxide by modified Na(1-x)LaxTaO(3+x) surface by V.Jeyalakshmi, NCCR. [11.40 TO 12.00 NOON]

10.HYDROTHERMAL SYNTHESIS OF Ce-TiO2 NANOTUBES FOR PHOTOCATALYTIC CO2REDUCTION- R. Ramya, M. Neelaveni and K. Shanthi , Department of Chemistry, Anna University, Chennai – 600025. [12.00 TO 12.20 P.M.]

11. Synthesis, characterization and photocatalytic activity of ordered mesoporous titania synthesized via hard-template route, Sanjeev Gupta and Parasuraman Selvam, National Centre for Catalysis Research and Department of Chemistry, Indian Institute of Technology Madras. [12.20 TO 12.40P.M.]

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HYDROTHERMAL SYNTHESIS OF Ce-TiO2 NANOTUBES FOR PHOTOCATALYTIC CO2REDUCTION

R. Ramya, M. Neelaveni and K. Shanthi*Department of Chemistry, Anna University, Chennai – 600025.

The explicit usage of fossil fuels in industries, transportation and deforestation increased the amount of CO2 in the atmosphere. CO2 is one among the long-lived greenhouse gases responsible for the global warming. The sorption of CO2 and its chemical transformation is a high energy process. Thus, alternative methods that can lower the reaction temperature are desired. Efficient conversion of CO2 to various reduced components can be achieved at low temperature using semiconductors as photocatalysts. Cerium ions (Ce3+ and Ce4+) doped titania showed a variety of photocatalytic applications.

In the present study, the results of photocatalytic reduction of CO2 over cerium incorporated titania nanotubes (TNT) are reported. The textural properties of the nanocomposites are correlated with their photocatalytic performance. Ce-incorporated TiO2 with different Ti/Ce ratio were prepared by sol-gel method. Titanium tetra isopropoxide and Ce(NO3)3.6H2O were used as the metal precursors. Hydrothermal synthesis of Ce-TiO2 nanotubes was carried out at 408K for 48h.

Titanium tetra isopropoxide (TTIP) was dissolved in 25 ml of ethanol and hydrolyzed using 50ml of H2O: Ethanol (1:1) mixture. The pH of the mixture was maintained at 3.5 using 0.1M H2SO4 to form a gel. Then aqueous solution of Ce(NO3)3.6H2O was added drop wise to the above gel and stirred for 1h.The resulted gel was aged at room temperature for 2 h. The white precipitate obtained was filtered, washed several times with water and dried at 343K for 12 h. This was then calcined at 774K for 4h. 4g of Ce-TiO2 powder was taken in 135 ml of 10N NaOH solution and stirred for 1h. Then the mixture was transferred to a teflon lined autoclave and maintained at 408K for 48h. The nanotubes formed were filtered and washed with 0.1N HCl solution followed by distilled water until the pH of the filtrate reached 7. The sample was dried at 393Kfor 12h and then calcined at 673K for 1h.

The physico-chemical characterization of the calcined Ce-TiO2 nanotubes was done by XRD, TEM, DRSUV-vis, FT-IR and BET. Ce-TiO2 nanotubes showed the characteristic reflections of anatase phase with a slight shift in 2θ value. Nitrogen sorption isotherm of Ce-TiO2 showed type-IV adsorption isotherm. Surface area increased with increase in metal content. HR-TEM images of Ce-TiO2 established the formation of nanotubes with uniform size. The incorporation of Ce4+ in TiO2 shifted the band gap energy towards the visible region which is confirmed by DRS UV-Visible analysis.

Ce-TiO2 nanotubes and powdered Ce-TiO2with different Ti/Ce ratio will be tested for photocatalytic reduction of CO2 in aqueous medium. The parameters like influence of irradiation time, hole scavenger, etc., will be monitored and the conditions will be optimised for the efficient conversion of CO2 to value added chemicals. The adsorption of CO2 is expected to increase due to the high specific surface area and porous nature of Ce-TiO2

and due to shift in the band gap energy towards the longer wave length.

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It is inferred that the framework incorporation of cerium ions decreases the band gap energy and may enhance the photocatalytic reduction of the CO2 in the visible region.Reference:

1. N.R. Sasirekha, S.J.S. Basha and K. Shanthi, Appl. Catal. B: Environ., 62 (2006) 169-180.2. Yangang Wanga, Bo Li, Chengli Zhang, Lifeng Cui, Shifei Kang, Xi Li, Lihui Zhou,

Applied Catalysis B: Environ., 130– 131 (2013) 277– 284

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HR-TEM image of Ce-TiO2, Ce-TNT and SAED pattern of Ce-TNT

XRD Pattern TiO2, TNT, 0.5 wt % of Ce-TNT and 1 wt% of Ce-TNT

A Soft-chemical approach for the synthesis Mo- Ni supported on Al-SBA-15 for hydrodenitrogenation of 2-propyl aniline

P. Santhana Krishnan, K. Shanthi*

Department of Chemistry, Anna University, Chennai – 25.*Corresponding Author: Contact No.:+91-44-22358654, kshanthiramesh@ yahoo.com

Introduction

The sulfide form gamma-alumina supported Mo or W promoted by Ni or Co has been used in industry for crude oil processing [1] [2] with additives such as phosphorus, boron and fluorine. In the recent times, the focus of the researchers is shifted to mesoporous materials like MCM-41 and SBA-15 as support for Ni-Mo catalyst because of their tunable acidity, well-defined hexagonal ordered porous structure, narrow pore diameter (3 - 30 nm). There is a serious concern over the process of sulphidation of the hydrotreating catalysts in industry due to stringent environmental regulations. It is extremely desirable to improve the characteristics of hydrotreating catalyst through judicious choice of process innovation. Owing to the concern over the use of hazardous sulphiding agents, a new method for the production of sulphide form of the molybdenum is attempted through soft chemical synthetic method as reported in the literature [5]. The activity of catalysts was tested for HDN of 2-propyl aniline using fixed bed flow reactor at atmospheric pressure and temperatures ranging from 623 to 673K.

ExperimentalThe siliceous SBA-15 with hexagonal structure synthesized as described in literature

[3]. Al-SBA-15 was synthesized via post-grafting alumination of SBA-15 using aluminum chloride as source [4]. Ammonium tetrathiomolybdate (ATTM) was synthesized by soft-chemical approach as in the patent [5] and respective 14 % MoS2/Al-SBA-15(10) was prepared by thermal decomposition of ATTM at 633 K for 3 h under N2 atmosphere through pore volume impregnation. 4 % Ni2P/Al-SBA-15(10) was prepared by thermal decomposition of mixed salts of NaH2PO2.H2O and NiCl2 in 1.5 molar ratio at 573 K for 1 h under N2

atmosphere by wet impregnation [6]. MN/AS (10) prepared by sequential wet impregnation of Ni2P/Al-SBA-15(10) followed by thermal decomposition of ATTM. The synthesized catalysts were characterized by low and high angle XRD, BET, TPD/TPR, UV-DRS, HRSEM and HRTEM. The activity of MoS2/Al-SBA-15(10), Ni2P/Al-SBA-15(10) and MoS2-Ni2P/Al-SBA-15 (10) were tested for HDN of 2-propyl aniline using fixed bed flow reactor at atmospheric pressure and temperatures ranging from 623 to 673K.

Results & Discussion

N2 adsorption-desorption isotherms (fig.1a) of siliceous SBA-15 and synthesized catalysts display type IV with an H1 hysteresis loop, which is a characteristics of mesoporous materials). Fig. 1b shows the peaks in wide angle XRD corresponding to the reflections (002), (100), (103), (105), and (110) confirming the formation of MoS2 on Al-SBA-15. N2

adsorption-desorption isotherm of MN/AS (10) showed a small decrease in surface area in table 1. However, the pore characteristic of the SBA-15 was maintained. The total amount of acid sites calculated from NH3-TPD studies is shown in table 1. Higher amount of acid sites provided by MoS2-Ni2P/Al-SBA-15 (10) has significant influence on HDN of 2-propyl aniline. Fig. 1c shows a direct relationship between the activity and the total amount of acid sites as a linear correlation through the origin of coordinates.

Conclusion

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Al-SBA-15 (10) supported MoS2, Ni2P were synthesised by simple soft chemical approach followed by thermal decomposition method. The design such as combination of MoS2 and Ni2P/Al-SBA-15 (10) separated by silica beds in a quartz tube and reverse order of impregnation of Ni2P first followed by MoS2. MoS2-Ni2P over Al-SBA-15 (10) support produced a more efficient catalyst. The impregnated catalyst showed high activity for HDN of 2-propyl aniline.

Fig. 1a Fig. 1b Fig. 1c

Table 1Textural and structural characteristic of SBA-15 supported catalyst

Sample SBET (m2/g) Vp (cm3/g) Dpb (A) Total acidity

(mmol NH3/g cat)Activity × 10-4 mol

h-1 g-1

Siliceous SBA-15 760 0.86 66 - -Al-SBA-15(10) 587 0.72 66 0.52 -MoS2/Al-SBA-15(10) 423 0.7 65.3 1.7 1.55Ni2P/Al-SBA-15 (10) 523 0.7 65.12 0.69 0.46MoS2-Ni2P/Al-SBA-15 (10) 278 0.37 38.12 3.29 2.57

References [1] B.C. Gates, H. Topsøe, Polyhedron 16 (1997) 3213.[2] F. van Looij, P. van der Laan, W.H.J. Stork, D.J. DiCamillo, J. Swain, Appl. Catal. A: Gen. 170 (1998) 1. [3] V. Meynen, P. Cool, E.F. Vansant, Microporous and Mesoporous Materials 125, (2009) 170–223[4] Tatiana Klimova, Javier Reyes, Oliver Gutierrez, Lilia Lizama, Applied Catalysis A: General 335, (2008) 159–171[5] Gabriel Alonso, Russell R. Chianelli, Sergio Fuentes, Brenda Torres, US 7,223,713 B2.[6] Qingxin Guan, Wei Li ∗, Minghui Zhang, Keyi Tao, Journal of Catalysis 263 (2009) 1–3

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Mesoporous SBA-15 supported

Rhenium catalysts for Hydrodenitrogenation of MCHA

I. Effect of Re loadingK.Sureshkumara, S.J.Sardhar Bashaa and K.Shanthi*b

a Department of Chemistry, Anna University, University College of Engineering, Ramanathapuram-623513.

b Department of Chemistry, Anna University, Chennai – 25.

1. Introduction Hydrotreating is an important process of petroleum refining industry. Hydrotreating is used

to remove heteroatoms like sulfur, nitrogen, oxygen and aromatics content of petroleum feedstocks. In recent years, hydrodenitrogenation (HDN) is an important industrial hydrotreating unit. Transition metal sulfided catalysts frequently used in hydrotreating reactions due to its high activity[1-4]. The conventional catalysts extensively used in hydrotreating reaction are molybdenum sulfide or tungsten sulfide promoted by cobalt or nickel supported on alumina. Under these circumstances, we need an alternative better catalyst for hydro treating reactions. Remarkably, Rhenium sulfide consists of higher activity than other transition metal sulfide because of the activity of rhenium is higher in magnitude in the volcano curve. The unsupported rhenium catalyst on hydrodenitrogenation (HDN) and hydrodesulphurization reactions were well studied. And also alumina and carbon supported Re catalyst shows higher activity for HDS and HDN of gas oil [5]. The modification of support alumina to silicates and aluminosilicates will provide better dispersion and thermal stability to the supported catalyst.

2. Experimental SBA-15 was synthesized by hydrothermal method [6]. Re metal supported on SBA-15 with

different Re loadings (1, 3, 5 and 7 wt %). An aqueous solution of ammonium perrhenate was used as precursor for Re. The synthesized supports and catalysts were characterized by XRD, DRUV-Vis, RAMAN spectra, N2-sorption studies, SEM, TEM, TPR and TPD techniques. The catalyst were pre sulfided at 400°C for 3 h using a ditertiary butyl polysulfide (DBPS) as sulfiding agent and hydrogen (1:20 mmol of DBPS:H2). The catalytic activity of synthesized catalyst xRe/SBA-15 (x=1, 3, 5 and 7 wt %) were tested for HDN of methylcyclohexylamine (MCHA).

3. Result and DiscussionWide angle XRD patterns of Re (x)/SBA-15 (x= 1, 3, 5, and 7wt %) catalysts shown in Fig.1

(a-d) which result in the oxide catalysts and did not show any additional diffraction lines of Re species. This may be due to strong indication of the highly dispersed Re species over the support. The total surface area and pore size of siliceous SBA-15 and Re/SBA-15 catalyst shown in Table 1. The isotherms clearly displays a typical type-IV along with inflections in the p/p0 value range of 0.6−0.8 (Fig.2).These results indicates that mesoporosity and ordered pore structure were maintained after optimum Re loading over the support

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Fig.1 Fig.2

Table 1 : Textural and structural characteristics of SBA- 15 support and catalysts.

4. ConclusionIn this study, we have

successfully synthesized rhenium impregnated SBA-15 materials. The various physico-chemical studies confirm that mesoporous nature of the catalyst. The catalytic activity of synthesized catalyst xRe/SBA-15 (x=1, 3, 5 and 7 wt %) were tested for HDN of MCHA. 5%Re loaded SBA-15 catalyst was the most active catalyst. The catalytic activity was correlated with characterization results.

References

1. C.S. Raghuveer, J.W. Thybaut , R. De Bruycker, K. Metaxas, T. Bera, G.B. Marin, Fuel,2014,206-218.

2. S. Eijsbouts, V.H.J. De Beer, R. Prins, Journal of Catalysis 127 (1991) 619–630.3. T.G. Harvey, K.C. Pratt, Applied Catalysis 47 (1989) 335–341. 4. Sardhar Basha, S. J.; Sasirekha, N. R.; Maheswari, R.; Shanthi, K. Appl. Catal., A 2006, 308,

91−98.5. Zhao, D.; Feng, J.; Huo, Q.; Melosh, N.; Fredrickson, G. H.; Chmelka, B. F.;

Stucky., G. D. Science 279 (1998), 548−552. 6. N. Escalona , J. Ojeda , R. Cid, G. Alves , A. Lopez Agudo,J.L.G. Fierro , F.J.

Gil Llambias , Applied Catalysis A: General 234 (2002) 45–54.7. N. Escalona , J. Ojeda , R. Cid, G. Alves , A. Lopez Agudo,J.L.G. Fierro , F.J.

Gil Llambias , Applied Catalysis A: General 234 (2002) 45–54.

Selective oxidation of adamantane over graphene supported CeO2 nanoparticles

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Catalysts SBET

(m2 g−1)b

Vp

(cm3 g−1)c

SBA-15 572 0.59

1%Re/SBA-15 410 0.51

3%Re/SBA-15 398 0.47

5%Re/SBA-15 371 0.43

7%Re/ SBA-15 292 0.41

A. Selvamani and K. Shanthi∗Department of Chemistry, Anna University, Chennai 600025, India

1. Introduction

The development of efficient methods to oxidize C–H groups of organics with molecular oxygen is a great important process for the industrial and pharmaceutical applications. Activation of the C–H bonds is appreciably more difficult due to its kinetic stability. Selective oxidation of adamantane is most important process due to its derivatives, especially mono- or di-substituted can be used as important precursors for photoresists, medicines and etc. In recent decades, various catalytic systems have been developed for the oxidation of adamantane molecule.

However, the oxidation adamantane molecule cannot efficiently catalyzed by simple transition-metal salts such as Co(ac)2, and Mn(OAc)2 under mild reaction conditions. Cerium oxide has been potentially used as catalyst for the oxidation of hydrocarbons due to its variable oxidation states (Ce3+ and Ce4+) along with their high oxygen storage capacity. In heterogeneous catalysis, catalytic activity is scaled with high surface area, fine dispersion of active particles (MO) and its specific morphology, which makes the invention of supported nanosized catalysts very tempting. Among the various supports, graphene oxide has been potentially used to various transition metal oxides owing to its high surface area, electric conductivity and thermal stability. The present work reveals that the oxidation of adamantane over graphene supported ceria nanoparticles. 2. Experimental

Graphene oxide was synthesized by Hummer’s method, and ceria nanoparticle (CeO2) was synthesized by reported procedure [3]. CeO2 nanoparticles loaded graphene oxide with various ratios (0.2, 0.4, 0.6 and 0.8 wt. %) were synthesized using wet impregnation method. The synthesized catalysts have been characterized by various characterization techniques. Crystalline nature of the catalysts was confirmed by XRD, and N2 sorption study is used to get the surface area. Oxidation state of cerium ion preset in the catalysts was identified from DRUV-Vis, and morphology of the catalysts was studied using SEM. Catalytic activity of the synthesized catalyst has been studied by selective oxidation of adamantane using oxygen as green oxidant. The oxidized products were analyzed in a gas chromatograph (Shimadzu 17A) equipped with a DB-5 capillary column (30 m×0.25 mm×0.25 µm) with flame ionization detector.3. Results and discussion

XRD was used to study the crystalline structure of GO and ceria loaded graphene oxide. Fig. 1a illustrates the XRD patterns of graphene oxide and appearance of broad diffraction peak at 2θ= 11.2◦ indicate that the graphene oxide was retained in layered structure. CeO2 loaded graphene oxide shows corresponding 2θ values (28.5◦, 33◦, 47.4◦ and 56.4◦) respect to the FCC structure of ceria (JCPD-43-1002), and existence of additional peak around 2θ= 11◦ is reveals that the presence of graphene oxide (Fig. 1b).

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Fig. 1

Fig. 2

Table 1 depicts the surface area of synthesized catalysts, and specific surface area of graphene oxide was decreased when the addition of ceria nanoparticles as given in the Table 1. Morphology of ceria and GO were shown in Fig. 2a & b, respectively. As shown in Table 1, CeO2(0.4)/ GO catalyst showed high conversion and adamantanone with maximum selectivity (Table 1), which is due to fine dispersion of CeO2 on GO and existence of prevalent Ce3+ ions.

Table 1Catalyst Surface area m2/g Adamantane

Conversion (%)AdamantanoneSelectivity (%)

CeO2 97 56 62GO 574 42 68

CeO2(0.2)/ GO 569 61 73CeO2(0.4)/ GO 562 68 83CeO2(0.6)/ GO 554 67 79CeO2(0.8)/ GO 541 67 79

ConclusionThe CeO2(x)/GO catalysts were synthesized and characterized with various

techniques, and catalytic activity results reveals that the CeO2(0.4)/GO is the suitable catalyst for selective oxidation of adamantane.

References[1] S. Shinachi, M. Matsushita, K Yamaguchi and N. Mizuno. J. Catal. 233, (2005) 81.[2] A. Bordoloi, A. Vinu and S.B. Halligudi, Appl. Catal A: Gen. 333, (2007) 143.[3] A. Selvamani, M. Selvaraj, M. Gurulakshmi, R. Ramya and K. Shanthi. J. Nanosci. Nanotechnol. 13, (2013) 1.

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a b

a b

M-TUD-1 as solid acid catalyst for one pot multicomponent synthesis of 1,4-Dihydropyridine derivatives

Department of Chemistry, Anna University, Chennai 600025, India, Tel.: +91-9176063575;E-Mail: maheswarianand@annauniv.com

Al and Zr containing mesoporous material (TUD-1) were investigated as greener catalyst for the synthesis of 1,4-dihydropyridine (DHP) derivatives via one pot multicomponent synthesis, namely Hantzsch reaction. The synthesised materials were characterized by Low angle, Higher angle XRD, N2 sorption, FT-IR, UV-Vis, TG-DTA, NH3 TPD and Pyridine adsorbed FT-IR. All studies confirm the mesoporous nature, co-ordination of metal and acidic nature respectively. Among the derivatives studied, the final isolated yield was measured as (65%) to maximum of (90%) yield. Some DHPs were obtained in shorter reaction times of 3h depending on the nature of substituents in benzaldehyde. Though these two catalyst possessed similar amounts of acidity, Zr-TUD-1 was found superior to Al-TUD-1.

Table 1.Physicochemical properties of the catalyst

Catalyst nSi/n(M)a nSi/n(M)

bSBET

c

(m2 g-1)

Vp,BJHd

(cm3 g-1)

Dp,BJHe

(nm)

Total Acidityf

(mmol NH3 g-1)

Al-TUD-1 40 33 558 0.91 6.5 0.30

Zr-TUD-1 40 46 452 0.72 5 0.27aSi/(Al+Fe) ratio in synthesis gel, bElemental analysis by ICP-OES, cSBET = Specific Surface Area, dVP,BJH = Pore Volume, edP,BJH= Pore Diameter, fCalculated from the NH3-TPD.

Table 2. Effect of various substituted aldehyde in Hantzsch reaction at 80°C

Entry AldehydeTime

(h) a

Isolated Yield (%) Mp (°C)

Al-TUD-1 (40) Zr-TUD-1 (40)Measured

1 Benzaldehyde 5 65 73 159-160

2 4-Bromobenzaldehyde 4 71 80 159-160

3 4-Chlorobenzaldehyde 4 75 89 148-149

4 4-Nitrobenzaldehyde 5 68 78 132-134

5 4-Methoxybenzaldehyde 4 75 86 160-161

6 Furan-2-carbaldehyde 3 80 87 159-160

7 Thiopene-2-carbaldehyde 3 82 90 165-167

8 Thiopene-2-carbaldehyde 6 38b 47c

aCompletion of the time monitored by TLCbAlCl3 and cZrOCl2 was employed as catalyst. (50 wt% with respect to total weight of substrates). Reaction conditions: Catalyst (100mg), substituted aldehyde (1mmol), ethyl acetoacetate (1mmol), ammonium acetate (1.2 mmol), ethanol (5ml).

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References

1. M. Syamala, Org. Prep. Proced. Int., 2009, 41, 1–68.

2. K. Kandasamy, M. P. Pachamuthu, M. Muthusamy, S. Ganesabaskaran, and A. Ramanathan, RSC Adv., 2013, 3, 25367–25373.

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Cu-Mn-TUD-1: A Bimetallic Catalyst for Ethyl benzene Oxidation

Cu and Mn were incorporated by varying the metal amounts into TUD-1support, synthesized via sol-gel technique using Cu(CH3COO)2 and Mn(CH3COO)2 as precursor. The XRD and N2 sorption studies of Cu-Mn-TUD-1 confirmed the amorphous mesoporous nature. N2 studies showed Type IV adsorption isotherm. The BET analysis of Cu-Mn-TUD-1 decreased approximately from 563 m2/g to 322 m2/g with an increase in Cu and Mn content. Pore diameter increased from 6.2nm to 9.8nm with Cu+Mn loading. The nature of Cu and Mn species were also characterized by DRS-UV, EPR and FT-IR studies. 3D worm-hole like mesopores was confirmed by HR-TEM. The synthesised bimetallic Cu-Mn-TUD-1 material was evaluated as catalyst for the oxidation of ethylbenzene using TBHP as oxidant and acetonitrile as a solvent at a temperature of 70o C to determine the effect of the Cu and Mn species residing on TUD-1. The well dispersed Cu-Mn mixed nano-particles possibly provide high active sites that lead to enhance higher conversion of ethylbenzene relative to mono metals in TUD-1.

Catalyst Si/Cu+Mn SBET (m2/g) Vp (cm3/g) Dp (nm)

Cu-Mn-TUD-1(100) 100 563 0.87 6.2

Cu-Mn-TUD-1(50) 50 451 0.90 8.0

Cu-Mn-TUD-1(10) 25 322 0.79 9.8

Catalyst Conversion

(%)

Selectivity (%)

AP 1-PE PhCHO

Cu-Mn-TUD-1(100) 60.1 85.4 11.3 3.3

Cu-Mn-TUD-1 (50) 72.3 89.9 7.9 1.2

Cu-Mn-TUD-1 (25) 82.6 71.6 19.4 9.0

Cu-TUD-1 (100) 35.2 67.0 20.0 10.3

Mn-TUD-1(100) 18.5 62.6 27.8 9.6

Reference :

1. Gaffar Imran, Muthusamy Poomalai Pachamuthu, Rajamanickam Maheswari, Anand

Ramanathan, S. J. Sardhar Basha Journal of Porous material, 5 (2012) 19, 677-682.

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Synthesis, characterization and photocatalytic activity of

ordered mesoporous titania synthesized via hard-template route

Sanjeev Gupta and Parasuraman Selvam

National Centre for Catalysis Research and Department of Chemistry

Indian Institute of Technology Madras, Chennai 600 036

Ordered mesoporous titania, designated as TNTA-15, was synthesized by nanocasting method using SBA-15 and titanium tetrabutyl orthotitanate as hard-template and precursor, respectively followed by etching the silica matrix with HCl and/or HF [1]. The synthesized materials was systematically characterized by various analytical, imaging and spectroscopic techniques, viz., XRD, BET, SEM, TEM, EDX, DRUV-VIS, PL and Raman. Well-characterized samples was employed for the photocatalytic hydrogen evolution reaction from water (source) and methanol (sacrificial agent). Figure 1 depicts the photocatalytic activity of mesoporous titania. Further work is in progress.

Fig.1 Photocatalytic hydrogen evolution over TNTA-15.

Reference

1. L. Zhao, Z. Yu, J. Colloid interface Sci. 304 (2006) 84-91.

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HYDRGENOLYSIS OF BIO-MASS DERIVED POLYOLS TO VALUE ADDED CHEMICALS

R. Vijaya Shanthi , S. Sivasanker

NCCR, Department of Chemistry, IIT- Madras, Chennai

Conversion of biomass to renewable chemicals and fuels has received significant attention as a means to a sustainable society. Cellulosic biomass, mainly consisting of carbon, hydrogen and oxygen, is the largest source of polyols, such as hexoses, pentoses and the corresponding alcohols. These polyols, including glycerol found in vegetable oils, can be transformed into commercially important alcohols and glycols, which are at present manufactured from petroleum sources. For example, sorbitol and glucose can be hydrogenolyzed into different oxygenates of much commercial use as shown in Fig. 1.

Fig. 1. The different products of the hydrogenolysis of glucose.

In this presentation, the transformation of sorbitol and glucose over different supported metal catalysts is presented. We had earlier reported our studies on Ni, Pt and Ru supported on NaY for hydrogenolysis of sorbitol [1].

As a continuation of our studies, we have investigated the hydrogenolysis of sorbitol and glucose over metal supported on synthetic strontium hydroxyapatite (HAP).The metals investigated are Ni, Pt and Ru and the support used is strontium hydroxyapatite . Nano-particulate strontium hydroxyapatite was synthesized by following a published procedure [2].

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Fig.2. XRD patterns of Sr-HAP & the catalysts (left) and SEM image of Sr-HAP (right)

The supported metal catalysts were prepared by impregnation of the support with suitable metals salts, calcination at 450 C and reduction in H2 at 400 C before use. The hydrogenolysis reactions were carried out in the temperature range of 180 – 220 C at pressures between 40 – 60 bars. XRD-patterns of the catalysts and a SEM picture of the nano-HAP sample are presented in Fig. 2. Ni/HAP was found to be the most active and selective (for glycols) one amongst all the catalysts. The influences of temperature, pressure and catalyst loading on conversion and product selectivity are presented. The reusability of the catalysts has also been investigated.

Reference:

[1] M. Banu, P. Venuvanalingam, R. Shanmugam, B. Viswanathan, S. Sivasanker, Topics in Catalysis (2012) 55:897–907.

[1] C. Sophie, J. Parastoo, M. Liam, K. Kajal , Materials Science and Engineering C 35 (2014) 106–114.

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Influence of basicity on photo catalytic reduction of carbon dioxide by modified Na(1-x)LaxTaO(3+x) surface

V. Jeyalakshmia,b, R. Mahalakshmyb, K.R Krishnamurthya and B. Viswanathana*

aNational Centre for Catalysis Research, Indian Institute of Technology, Madras,Chennai,600036,India

bDepartment of Chemistry, Thiagarajar College, Madurai Kamaraj University, Madurai,625021, India

Increase in atmospheric carbon dioxide concentration, and limited fossil fuel resources have initiated research the conversion of CO2 chemicals/fuels. In this context, photo catalytic reduction of CO2 using water as reductant is one of the most promising approach. The process uses renewable and abundant resources like CO2, water & sun light, that enables the development of a carbon neutral alternative source to fossil fuels and ultimately helps in the abatement of atmospheric CO2 levels. Tantalum based perovskites have been investigated as potential photoactive material, particularly Na (1-x)LaxTaO(3+x) photo catalyst is one among the efficient materials for water splitting under UV irradiation. Its application is limited to UV region in the solar spectrum due to its high band gap (4eV). Doping with various elements (Fe, Bi, Cu, N, S) has been one of the strategies adopted to achieve visible light photo catalysis by tantalates.

In this paper, we have investigated the effect of co-doping of MgO with Fe & N on Na(1-x)LaxTaO(3+x) catalyst, so as to increase adsorption of CO2 on Na(1-x)LaxTaO(3+x) surface. Fe and N doped Na(1-x)LaxTaO(3+x) was synthesized by hydrothermal method ( ) MgO with various concentrations was introduced on N & Fe doped Na(1-x)LaxTaO(3+x) by impregnation method. The synthesized materials were characterized by XRD, DRS UV visible spectroscopy, Fluorescence spectra, BET, SEM, TEM, XPS and Temperature-programmed desorption (TPD) of CO2. Photo catalytic reduction of carbon dioxide with the synthesized material gives methanol as major product under our experimental conditions. Co-doped (Fe-N) Na(1-x)LaxTaO(3+x) shows significant activity compared to mono doped Na(1-x)LaxTaO(3+x).

Among the MgO loaded samples, the formulation with 0.5Wt% loading shows maximum Quantum yield ( Fig.1) due to increase in CO2 adsorption. n MgO loaded Fe/N/Na(1-

x)LaxTaO(3+x) surface.

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Fig.1 Comparison of AQY data on various modified NaTaO3

References

1. Y. Izumi, Coord. Chem. Rev., 2013, 257, 171; V. Jeyalakshmi, K. Rajalakshmi, R. Mahalakshmy, K. R. Krishnamurthy and B. Viswanathan, Res. Chem. Intermed., 2013, 39, 2565; V. Jeyalakshmi, R. Mahalakshmy, K. R. Krishnamurthy and B. Viswanathan, Matl. Sci. Form, Trans Tech. Pub, Switzerland, 2013, 734, pp. 1–62; T. J. Meyer, J. M. Papanikolas and C. M. Heyer, Catal. Lett., 2011, 141, 1.

2. Peng Zhang, Jijie Zhang and Jinlong Gong, Chem. Soc. Rev., 2014, 43, 4395—4422 3. V. Jeyalakshmi, R. Mahalakshmy, K.R. Krishnamurthy, B. Viswanathan, - 6th Asia Pacific Congress on Catalysis-APCAT-6, Oct 13-17, 2013, Taipei,Tai. 4. Pushkar Kanhere et al., Phys. Chem. Chem. Phys., 2014, 16, 16085—16094. 5. V. Jeyalakshmi, R. Mahalakshmy, K Ramesh, P V C Rao, N V Choudary, G Sriganesh, K. Thirunavukkarasu, K.R Krishnamurthy , B. Viswanathan, RSC Advances 5, 2015, 5958

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Mesoporous silica-templated synthesis of ordered mesoporous copper oxide

T. V. R. Mohan and P. Selvam

National Centre for Catalysis Research and Department of Chemistry

Indian Institute of Technology Madras, Chennai 600 036

The design and synthesis of mesoporous metal oxides with high thermal stability, large surface area, and crystalline framework have attracted considerable interests in the recent years due to their applications in the areas viz., adsorption, separation, catalysis, sensors, photonics and nano-devices. Only a few attempts have been made to prepare ordered porous transition metal oxides in particular copper oxide as the thermal treatments to remove the template leads to collapsing of the pores structures. Ordered mesoporous cupric oxide has been synthesized using ordered mesoporous silica (KIT-6/SBA-15) hard template and copper nitrate precursor by impregnation-ammoniation process. The resulting mesoporous cupric oxide, designated as TNCU-6, TNCU-15, is systematically characterized by various analytical and spectroscopic techniques. The wall thickness of silica hard template is equal to the pore diameter of mesoporous copper oxide, which shows that the obtained material is exact inverse replica of the silica template.

200.0 0.2 0.4 0.6 0.8 1.0

TNCU - 6

P/P0

Qua

ntity

Ads

orbe

d (a

.u.)

KIT - 6

0 2 4 6 8 10D (nm)

dV

/d(lo

gD)

(b)

0.0 0.2 0.4 0.6 0.8 1.0

TNCU - 15

SBA - 15

P/P0

Qua

ntity

Ads

orbe

d (a

.u.)

0 2 4 6 8 10D (nm)

dV

/d(lo

gD)

(a)

1 2 3 4 5 6 70

250

500

750

1000

2 (deg).

Intens

ity (c

ps)

10 20 30 40 50 60 70 80

600

800

1000

1200

1400

1600

1800

133411331

222012

211

220

101

2 (deg).

Intensity

(cps)

020

011

120

311

112

122

131

14003

1

111

200

400

160

340

(a)

800 1200 1600 2000

LiFePO4/C

D-band

Intensity

(a.u.)

LiMnPO4/C

G - band

Raman shift (cm-1)

(b)

Fig. 1. BET isotherms of: (a) SBA-15 and TNCU-15; (b) KIT-6, and TNCU-6.

Inset: Pore size distribution.

References

[1] Tae-Wan, K.; Kleitz, F.; Paul, B.; Ryoo, R.; J. Am. Chem. Soc., 2005, 127, 7601-7610.[2] Zhao, D.; Feng, J.; Huo, Q.; Melosh, N.; Fredrickson G. H.; Chmelka B. F.; Stucky, G. D.;

Science, 1998, 279, 548-549.[1] Ren, Y.; Ma, Z.; Qian, L.; Dai, S.; He, H.; Bruce, P. G.; Catal Lett, 2009, 131, 146–154.

Mesoporous LiMPO4 (M = Fe or Mn) - Carbon Composites:

Synthesis and Characterization

Sourav Khan and Parasuraman Selvam

National Centre for Catalysis Research, Department of Chemistry,

Indian Institute of Technology Madras, Chennai 600 036, India

Olivine-structured LiMPO4 (M = Fe or Mn) has been regarded as one of the promising cathode materials for Li-ion batteries owing to low cost, safety and long-life span. However, low electronic conductivity (<10−10 S cm−1) and sluggish lithium ion diffusivity (~10-14 cm2 s−1) are inherent drawbacks of bulk LiMPO4

1,2. Furthermore, it is more difficult to obtain an efficacious conductive carbon coating on LiMPO4 due to the less reactive nature of the compound to the carbon source. On the other hand, a simple sol-gel method employed to synthesize LiMPO4/Carbon (M = Fe or Mn) nanocomposite show promise3-6. In this work, we report the synthesis and characterization of ordered mesoporous LiFePO4/Carbon and LiMnPO4/Carbon composites using citric acid, as chelating agent and carbon source. Figure 1 depicts the powder XRD pattern of the LiMnPO4/Carbon composite which exemplify good crystallinity and phase purity of the materials. As expected, the Raman spectra of the composites showed part of the carbon is of graphitic nature in the mesoporous framework structure. In summary, the methodology adopted for the preparation of LiMPO4/Carbon nanocomposites permits homogeneous carbon coating, in addition to the mesoporosity, which may be useful as cathode material for lithium-ion battery application.

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Fig. 1: a) XRD pattern of LiMnPO4/C, and b) Raman spectra of LiMPO4 (M = Fe and Mn)/C.References

[1] Padhi, A. K.; Nanjundaswamy, K.S.; Goodenough, J.B. J. Electrochem. Soc. 1997, 144, 1188.

[2] Zhang, S.; Meng, F. L.; Wu, Q.; Liu, F. L.; Gao, H.; Zhang, M.; Deng, C. Int. J. Electrochem. Sci. 2013, 8, 6603.

[3] Tarascon, J. M.; Armand, M. Nature 2001, 414, 359.

[4] Selvam, P.; Khan, S.; Bhunia, K.; Milev, A.; George, L.; Gounder, A.; Kannangara, G.S.K. Asia-Pacific Conf. on Electrochem. Energy Storage and Conversion (APEnergy-2014), Feb 5-8, 2014, Brisbane, pp. 81.

[5] Gounder, A.; Milev, A.; Kannangara, G.S.K.; George, L.; Selvam, P. Asia-Pacific Conf. on Electrochem. Energy Storage and Conversion (APEnergy-2014), Feb 5-8, 2014, Brisbane, pp. 114.

[6] Khan, S.; Selvam, P. Int. Conf. on Electrochem. Sci. Technol., Aug. 7-9, 2014, Bengaluru, pp.107.

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