On the influence of Si:Al ratio and hierarchical porosity of FAU zeolites in solid acid catalysed esterification pretreatment of bio-oil

a Amin Osatiashtiani, b Begoa Purtolas, c Caio C. S. Oliveira, a Jinesh C. Manayil, a Brunella Barbero, a Mark Isaacs, d Chrysoula Michailof, d Eleni Heracleous, b Javier Prez-Ramrez, a Adam F. Lee, a Karen Wilson*

a European Bioenergy Research Institute, Aston University, Birmingham B4 7ET, UK.

b Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, CH-8093 Zurich, Switzerland.

c Technological Research Institute (IPT), 05508-901, So Paulo, Brazil.

d Chemical Process & Energy Resources Institute Centre for Research and Technology-Hellas (CPERI/CERTH) 6th km Harilaou-Thermi Road, 57001,Thessaloniki, Greece.

* E-mail: k.wilson@aston.ac.uk; Tel: +44 121 204 5456

Electronic Supporting Information

Table S1. Surface elemental analysis of FAU zeolite catalysts by XPS

Nominal

Si:Al ratio

Concentration / wt%

Concentration / At%

Si:Al atomic ratio

O

Si

Al

O

Si

Al

2.6

46.3

32.1

21.5

59.9

23.7

16.5

1.4

6

48.5

42.4

9.2

62.1

30.9

7.0

4.4

30

47.8

50.4

1.9

61.6

37.0

1.4

25.9

HFAU30

48.8

49.2

2.1

62.5

35.9

1.6

23.0

Figure S1. Schematic of in-situ ATR-IR flow cell.

Figure S2. XRD patterns for FAU zeolites.

Figure S3. Surface atomic concentration of Si and O from quantification of Si 2p and O 1s XP spectra as a function of Si:Al ratio in FAU zeolites.

Figure S4. ATR-IR spectra of acetic acid adsorbed over FAU2.6 as a function of time.

Figure S5. ATR-IR spectra of acetic acid adsorbed over FAU6 as a function of time.

Figure S6. ATR-IR spectra of acetic acid adsorbed over FAU30 as a function of time.

Figure S7. ATR-IR spectra of the Methoxy group region during the adsorption of acetic acid. At 0 min (black line) only methanol is adsorbed on the catalyst surface. After 30min of acetic acid flow (red line) the Methoxy peak is more broad and negative because of the competitive adsorption between the solvent and the probe molecule.

Figure S8. Esterification of acetic acid with various alcohols in an alcohol-rich media over FAU zeolites with 2.6 (), 6 (), 30 () Si:Al ratio and HFAU zeolite (). (Reaction conditions: 5 mmol acetic acid, acid:alcohol = 1:5 mol:mol, 10 ml toluene, 100 mg catalyst, 100 C)

Figure S9. Acetic acid conversion and ester selectivity as a function of FAU zeolite Si:Al ratio for esterification with a) benzyl alcohol and b) anisyl alcohol. (Reaction conditions: 5 mmol acetic acid, acid:alcohol = 1:5 mol:mol, 10 ml toluene, 100 mg catalyst, 100 C, 3h)

Figure S10. Esterification of acetic acid with methanol (), anisyl alcohol (), benzyl alcohol (), p-cresol () and n-butanol () over FAU30. (Reaction conditions: acid:alcohol = 1 (left), 5 (right), 10 ml toluene, 100 mg catalyst, 100 C)

00.020.040.0611001200130014001500160017001800AbsorbanceWavenumber / cm-10 min1 min2 min3 min4 min5 min10 min20 min25 min30 minFAU2.6

00.020.040.0611001200130014001500160017001800AbsorbanceWavenumber / cm-10 min1 min2 min3 min4 min5 min10 min20 min25 min30 minFAU6

00.020.040.0611001200130014001500160017001800AbsorbanceWavenumber / cm-10 min1 min2 min3 min4 min10 min15 min20 min25 min30 minFAU30

-0.03-0.025-0.02-0.015-0.01-0.0050270029003100AbsorbanceWavenumber / cm-10 min30 min

0204060060120180

Acid conversion / %Time / min

p-cresol

0204060060120180

Acid conversion / %Time / min

n-butanol

020406080060120180Acid conversion / %Time / minBenzyl alcohol

020406080060120180Acid conversion / %Time / minAnisylalcohol

020406080100060120180

Acid conversion / %Time / min

Methanol

0204060802.6630Acid conversion, benzyl acetate selectivity / %Si:Al ratioSelectivityConversion(a)

0204060802.6630Acid conversion, anisyl acetate selectivity / %Si:Al ratioSelectivityConversion(b)

020406080100060120180Acid conversion / %Time / minAcid:alcohol ratio = 1

0510152025060120180

Acid conversion / %Time / min

Acid:alcohol ratio = 5

10203040506070802HFAUFAU30FAU6FAU2.6

0204060800102030At. %Si:Al Atomic Ratio(Si) - O-AlSi - (O) - Al