Of Vanillyl Alcohol, Vanillin and Lign

Electronic Supplementary Material (ESI) for Green Chemistry. This journal is © The Royal Society of Chemistry 2020

Electronic Supplementary Information

Improved Pd/Ru metal supported Graphene oxide nano-catalysts for hydrodeoxygenation (HDO) of Vanillyl alcohol, Vanillin and

Lignin

Shalini Arora,a Neeraj Guptab and Vasundhara Singha*

a Department of Applied Sciences (Chemistry), Punjab Engineering College (Deemed to be University), Chandigarh-160012, INDIA Tel: +91-9888222214; E-mail: [email protected]

b School of Chemistry, Faculty of Basic Sciences, Shoolini University, Solan (H.P.)- 173212, INDIA, Tel: +918894211891; E-mail: [email protected]

1 Contents

1. General Method.………………………………………………………………..S3 2. Procedure for Catalyst preparation...... ………………………………………....S3 3. Procedure for HDO reaction, Photo-catalytic fragmentation…………...... S4 4. Comparison Table……………………………………………………………….S5 5. HPLC-MS results and Tables………………………………………………..S6, S7 6. Supplementary Figures and HPLC chromatograms...……………………….S8-S20

2 Supplementary Material

General Methods

Vanillin, Vanillyl alcohol, Graphene oxide, Palladium (II) chloride, Ruthenium (II) chloride and Lignin were purchased from Sigma Aldrich and TCI. Tetrahydrofuran and concentrated hydrochloric acid were procured from Alfa Aesar. All the reagents were used without any further purification. Perkin Elmer RXI-FTIR and Panalytical’s X’Pert Pro- XRD were used to record the FTIR and XRD data of the catalysts. JSM 6100 (JEOL) analytical instrument for EDS analysis, Nexsa base, XPS instrument for recording the X-Ray photoelectron spectroscopy, ARCOS, simultaneous ICP-AES-MS (induced coupled plasma) spectrometer for measuring the metal content. Waters 515 HPLC pumps, Waters 2998 PDA detector, manual single injection system and Empower 2 software were used for developing the calibration curves and for monitoring the reaction.

Method for preparation of Catalysts

A 20 ml solution containing 2.5 wt% each of the palladium chloride/ ruthenium chloride was prepared by adding 0.5 mL HCl and remaining deionized water. The resulting 0.01M solution (0.5 mL) was mixed with GO (0.3 g) and ultra-sonicated to completely disperse and exfoliate GO. Subsequently, the mixture was transferred to a borosil dish and placed in the center of the tube furnace. The temperature of the furnace was raised to 200oC at a rate of 10oC/min under an argon atmosphere. After attaining a temperature of 200oC, hydrogen gas was purged into the furnace and the atmosphere was maintained for 2 h. The furnace was cooled to room temperature and the treated sample was labeled as Pd/Ru@GO. Further, Pd@GO and Ru@GO were also prepared by the same protocol using 5 wt% of Pd and Ru metal solutions respectively.

3 Hydrodeoxygenation (HDO) of Vanillyl alcohol and Vanillin

The conversion of vanillyl alcohol (4-hydroxy-3-methoxy benzylalcohol)/ vanillin (4-hydroxy-3- methoxy benzaldehyde) was performed in a high pressure stainless steel reactor of 100 mL capacity as shown in Scheme 1. Vanillyl alcohol (0.1 g, 0.649 mmol), catalyst (0.01 g, 0.083 mmol) and 10 mL of methanol were stirred at ambient temperature in the reactor for 12 h at 145 psi H2 pressure. Similarly, for HDO of vanillin (0.1 g, 0.657 mmol), it was loaded with catalyst (0.02 g, 0.166 mmol) and 10 mL of methanol and stirred at ambient temperature in the reactor for 24 h at 145 psi H2 pressure. H2 gas was released and the catalyst was allowed to settle, filtered and the solution was analyzed by HPLC.

HO Catalysts O O OH OH

vanillin 145 psi H2, Methanol (10 mL) OCH3 Room Temperature +

HO p-creosol p-cresol

OH Catalysts Major product Minor product O

vanillyl alcohol Scheme. 1 Schematic representation of HDO of Vanillyl alcohol and Vanillin

Photo-catalytic experiment of Lignin

Photo-catalytic fragmentation of commercial lignin was carried out at room temperature in an immersion photo-chemical reactor made of Pyrex glass equipped with a circulating cooling water jacket using 0.3 g Degussa P-25 TiO2 added to 200 mL of lignin solution (0.2 g in 200 mL H2O) and the solution was kept in the dark for adsorption for 30 min.38 The suspension was then subjected to irradiation under UV light (125 W) with magnetic stirring for 5 h. After the UV treatment the sample was centrifuged to recover the catalyst. The clear aqueous fraction was extracted using dichloromethane and the solvent was evaporated under reduced pressure to give mixture of products mainly comprising of phenolic compounds. The phenolic compounds obtained were analyzed using HPLC-MS.

4 Comparative Study

Table S1. Comparative study of hydrodeoxygenation (HDO) of Vanillin Entry Catalyst/ Catalyst Reaction Conversion Product Reference Loading Conditions /selectivity (%) 1 Pd/C (50 mg) 100oC, 10 bar, 3 99/99 p-creosol 23 h octane-water 2 Ru/C (0.5 kg/m3) 55oC, 13.8 bar, 100/91 Vanillyl alcohol 24 1 h, water 3 Pt/AC, Rh/AC, Pd/AC, 100oC, 30 bar, 3 99/95 p-creosol 25 Au/AC and Ru/C (50 mg) h water o 4 Cu-Ni/SiO2(10 mg) 150 C, 25 bar, 96/76 p-creosol 26 12 h, water, 5 Pd/KIT-6 (5 wt%) 300oC, 6 h, 98/94 p-creosol 27 Methanol, atm pressure 6 Pd/Carbon nitride (10 mg) 70oC, 10 bar, 1 99/98 p-creosol 28 h, water 7 Ru/CNT (0.2 mol %) 150oC, 10 bar, 3 100/96 p-creosol 29 h, decalin- water 8 Au/CNT (0.68 mol %) 150oC, 10 bar, 6 94/100 p-creosol 30 h, decalin o 9 MO2C (50 mg) 180 C, 10 bar, 3 100/94 p-creosol 31 h, water o 10 Ni/SiO2-ZnO2 300 C, 50 bar, 100/54 hydrocarbons 32 16 h octane

5 LCMS Analysis: The LCMS of crude sample obtained by photo-degradation of commercial lignin and after HDO showed peak at m/z value corresponding to M/M+1/M+2 for various phenolic molecules.

Table S2. Possible products obtained from photo-catalytic fragmentation of commercial Lignin Entry Compound identified in DCM Chemical Structure Retention Time (min) LCMS m/z extract [M+1] 1. Tetrahydro-2Hpyran O 3.43/ 12418.24 88.15

2. 4-hydroxy-2methoxy HO 3.43/ 12418.24 153.10 benzaldehyde O O 3. 2,6-dimethoxybenzoquinone O 3.43/ 12418.24 169.12

O O O 4. 4-formyl-2-methoxyphenyl acetate 3.43/ 12418.24 195.76 O O O

O 5. 2-methoxy-1,4-phenylene 3.43/ 12418.24 223.16 O O diacetate O O O 6. Syringylglyoxalic Acid O 5.90/ 53249.86 242.00 HO O OH O O 7. 4-(3-methoxy-5-vinylphenoxy)-3- 3.43/ 12418.24 267.16 vinylphenol O O H O

8. 3,3-(ethane-1,2-diylbis(oxy))bis O 7.01/ 296859.09 307

(4-hydroxybenzaldehyde) enol OH O O OH

Table S3. Possible phenolic products obtained using Pd/Ru@GO after HDO of phenolic compounds obtained by photo-catalytic fragmentation of commercial Lignin Entry Compound identified in DCM Chemical Structure Retention Time (min) LCMS m/z extract [M+1] 1. Phenol 7.18/ 77342.57 94.00 OH 2. 4-methyl phenol OH 7.18/ 77342.57 109.02

6 3. 2-methoxy-4-methyl phenol OH 3.52/ 38917.05 139.02

O 4. 4-hydroxy-3-methoxy HO 4.75/ 5114.70 153.10 benzaldehyde O O 5. 4-hydroxy-3-methoxy HO 7.18/ 77342.57 154.00 benzylalcohol OH O 6. 4-(3-hydroxyprop-1-en-1-yl)- OMe 7.26/ 77342.57 211.00 2,6-dimethoxyphenol HO MeO OH HO 7. 2-hydroxy-4-methylphenoxy- O 7.076/ 77342.57 275.02 4methoxyphenyl ethanone O

Table S3. Possible phenolic products obtained using Ru@GO after HDO of phenolic compounds obtained by photo-catalytic fragmentation of commercial Lignin Entry Compound identified in DCM Chemical Structure Retention time LCMS m/z extract (min) [M+1] 1. 4-hydroxybenzaldehyde OH 4.77 123.04 O 2. 2-methoxyphenol OH 12.66 137.46

OCH3 3. 4-hydroxy-3-methoxy HO 4.77 152.04 benzaldehyde O O 4. 4-hydroxy-3-methoxy HO 7.06 154.00 benzylalcohol OH O 5. 4-(1-hydroethyl)-2- OCH3 4.77 167.07 methoxyphenol OH HO 6. 4-(3-hydroprop-1-en-1-yl)-2- H3CO 12.66 181.48 methoxyphenol HO OH 7. 2-(4-hydroxyphenyl)-5— OH 12.66 261.51 methoxy-2,3- O dihydrobenzofuran-7-ol HO OCH3

7 Supplementary Figures

Fig. S1 (a) XPS graph of Pd 3d in Pd@GO, (b) XPS graph of Ru 3p in Ru@GO, (c) XPS graph of Pd 3d in Pd/Ru@GO, (d) XPS graph of Ru 3d in Pd/Ru@GO.

100 Pd/Ru@GO Pd/Ru@GO

98 y= 59.72028x + 83.76084 R2= 0.93262

Ru@GO 96 ) % (

d l

e 94 i Y

90 Pd@GO

0.10 0.15 0.20 0.25 0.30 A

Fig. S2 Relationship between possible hydrogenation components (Pd and Ru), the O=C-O content and the yield of the product.

Fig. S3 EDS spectrum of Pd@GO, Ru@GO and Pd/Ru@GO.

HPLC analysis: The product was quantified by HPLC using PDA detector with a Waters Spherisorb 5µm ODS2 (4.6 X 250mm mm) C-18 (c)reverse phase column. The HPLC conditions for analysis of product were; column temperature; 30oC, methanol: water (1:1) as an eluent with flow rate of mobile phase 1.0 mL/min, injection volume 10μL with 20 minutes injection run time.

Fig. S4 HPLC Chromatogram showing complete conversion of vanillin by HDO to vanillyl alcohol using Pd/Ru@GO.

9 Fig. S5 HPLC Chromatogram showing complete conversion of vanillin by HDO to vanillyl alcohol using Ru@GO.

Fig. S6 HPLC Chromatogram shows complete conversion of vanillin by HDO to p-Creosol and p- Cresol using Pd/Ru@GO.

10 Fig. S7 HPLC Chromatogram shows complete conversion of vanillin by HDO to p-Creosol and p- Cresol using Ru@GO.

Fig. S8 HPLC Chromatogram shows complete conversion of vanillyl alcohol by HDO to p-Cresol and p-Cresol using Pd/Ru@GO.

11 Fig. S9 HPLC Chromatogram of Vanillin HDO using Pd/Ru@GO with benzophenone.

Fig. S10 HPLC Chromatogram of Vanillyl alcohol HDO using Pd/Ru@GO with benzophenone.

12 Fig. S11 HPLC Chromatogram of Vanillin HDO using Pd/Ru@Al2O3.

Fig. S12 HPLC Chromatogram of Vanillyl alcohol HDO using Pd/Ru@Al2O3.

13 WATERS,Q-Tof MICROMASS(ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-PD+ Sm (Mn, 2x3) 2: Diode Array 3.13 279 15546 Range: 2.889e-2 28321 Area, Height Time Height Area Area% 3.13 28321 15546.41 88.36 2.6e-2 4.48 4856 2047.50 11.64

2.4e-2

2.2e-2

2.0e-2

1.8e-2

1.6e-2 U

A 1.4e-2

1.2e-2

1.0e-2

8.0e-3 4.48 2047 6.0e-3 4856

4.0e-3

2.0e-3

0.0 Time 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50

Fig. S13 HPLC-MS graph showing m/z peaks values for different possible phenolic compounds of photo-degradation of commercial lignin.

WATERS,Q-Tof MICROMASS(ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-PD+ 2: Diode Array 3.12 279 3.0e-2 Range: 3.045e-2

2.0e-2 U A 1.0e-2 4.42 9.15 22.58 24.77 0.0 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 SHALINI L-PD+ 2: Diode Array 3.12 290 Range: 2.43e-2 2.0e-2 U A 1.0e-2 3.57 4.42 9.15 22.58 24.77 29.63 0.0 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 SHALINI L-PD+ 1: TOF MS ES+ 3.99 100 139 4.12 2.76e3

4.36 %

0 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 SHALINI L-PD+ 1: TOF MS ES+ 5.90 100 242 4.57e3 %

0 Time 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50

Fig. S14 HPLC-MS graph showing m/z peaks values for different possible phenolic compounds of photo-degradation of commercial lignin.

14 WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-PD+ 185 (3.431) Cm (185:218-(226:397+63:140)) 1: TOF MS ES+ 130.21 100 142 142

167.12 100

% 267.16 167.72 65 153.10 61 60

130.73 48

88.15 223.16 33 195.12 34 267.93 30 223.14 28 88.57 169.12 30 409.28 27 22 24 195.76 129.52 139.08 235.13 263.15 17 16 17 113.06 14 193.76 14 377.20 10 10 307.17 65.06 321.18 7 10 391.20 6 7 5

0 m/z 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500

Fig. S15 HPLC-MS graph showing m/z peaks values for different possible phenolic compounds of photo-degradation of commercial lignin.

WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-PD+ 318 (5.897) Cm (310:339-(354:423+196:253)) 1: TOF MS ES+ 242.36 100 6.32e3 6315 %

243.09 2066

243.37 1248

244.09 363

0 m/z 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540

Fig. S16 HPLC-MS graph showing m/z peaks values for different possible phenolic compounds of photo-degradation of commercial lignin.

15 WATERS,Q-Tof MICROMASS(ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-Pd-HDO- Sm (Mn, 2x3) 2: Diode Array 7.18 254 1.7e-1 77343 Range: 1.734e-1 170893 Area, Height Time Height Area Area% 1.6e-1 2.02 1178 178.29 0.14 3.52 71466 38917.05 31.57 1.5e-1 4.75 14361 5114.70 4.15 5.65 2507 998.07 0.81 7.18 170893 77342.57 62.73 1.4e-1 11.23 1397 473.01 0.38 21.70 1339 209.95 0.17 28.63 372 55.54 0.05 1.3e-1

1.2e-1

1.1e-1

1.0e-1

9.0e-2 U 3.52 A 8.0e-2 38917 71466

7.0e-2

6.0e-2

5.0e-2

4.0e-2

3.0e-2 4.75 5115 2.0e-2 14361 5.65 1.0e-2 2.02 998 11.23 21.70 28.63 178 2507 473 210 56 1178 1397 1339 372 0.0 Time 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00

Fig. S17 HPLC-MS graph showing different peaks of possible products of HDO of phenolic compounds of commercial lignin using Pd/Ru@GO.

WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-Pd-HDO 381 (7.076) Cm (374:398-401:426x2.000) 1: TOF MS ES+ 275.03 100 810 810

243.02 398 %

138.02 153.01 211.00 203 206 204 154.00 275.79 137.02 153 165 146 297.01 127 109.02 105 243.74 301.07 81.04 94.00 111.00 241.00 71 68 69 65 82 159.99 56 45 273.02 441.21 211.66 52 309.11 36 37 41 0 m/z 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500

Fig. S18 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Pd/Ru@GO.

16 WATERS,Q-Tof MICROMASS(ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-PD+ 2: Diode Array 3.12 279 3.0e-2 Range: 3.045e-2

4.36 %

0 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 SHALINI L-PD+ 1: TOF MS ES+ 5.90 100 242 4.57e3 %

0 Time 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50

Fig. S19 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Ru@GO.

WATERS,Q-Tof MICROMASS(ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-HDO 2: Diode Array 14.30 290 1.5e-2 Range: 2.739e-2

14.65 1.0e-2 U A

5.0e-3

0.13 12.57 0.0 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00 SHALINI L-HDO 2: Diode Array 14.30 270 1.5e-2 14.65 Range: 2.757e-2

1.0e-2 U A

5.0e-3 12.55

0.13 15.98 0.0 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00 SHALINI L-HDO 1: TOF MS ES+ 15.45 100 TIC 15.67 1.58e5 %

19.55 0.02 4.70 0 Time 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00

Fig. S20 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Ru@GO.

17 WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-Pd-HDO- 257 (4.775) Cm (238:259-288:326x2.000) 1: TOF MS ES- 123.04 100 332 332

167.07 296

152.04 172 %

122.04 135.04 96 101

137.06 71

120.01 168.06 34 31 319.09 333.10 23 29 107.04 215.04 234.00 22 15 15

0 m/z 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480

Fig. S21 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Ru@GO.

WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-Pd-HDO 381 (7.076) Cm (374:398-401:426x2.000) 1: TOF MS ES+ 275.03 100 810 810

243.02 398 %

Fig. S22 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Ru@GO.

18 WATERS,Q-TOF MICROMASS (ESI-MS) SAIF/CIL,PANJAB UNIVERSITY,CHANDIGARH SHALINI L-HDO 709 (12.668) Cm (700:709) 1: TOF MS ES+ 261.5189 100 313 313

59.3904 260

137.4660 232 % 100.4590 137

475.5289 59.7471 453.6130 102 91 181.4879 90 87 262.2590 68 476.5267 69.4256 275.4773 453.5405 100.9228 53 52 51 60 46 239.5454 203.4637 43 37 407.4929 303.4479 345.4841 28 22 23 477.5894 679.5769 701.4514 385.5127 14 13 12 15

0 m/z 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 625 650 675 700 725 750 775 800

Fig. S23 HPLC-MS graph showing m/z peaks values of possible products of HDO of phenolic compounds of commercial lignin using Ru@GO.

Fig. S24 FT-IR of bimetallic Ru@GO after seventh recycles.

19 Fig. S25 FT-IR of bimetallic Pd/Ru@GO after seventh recycles.