SUPPORTING INFORMATION

Producing High Yield of Levoglucosan by Pyrolyzing Non-thermal Plasma-

Pretreated Cellulose

Lusi A1, Haiyang Hu2, Xianglan Bai1*

1Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA2Department of Aerospace Engineering, Iowa State University, Ames, IA 50011 USA

*Corresponding author, Email: bxl9801@iastate.edu

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

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-5000

0

5000

10000

-0.010

-0.005

0.000

0.005

0.010

0.015U I

Vol

tage

[V]

Cur

rent

[A]

Fig S1. Voltage-current graph during plasma treatment

Fig S2 (a). Snapshot of cellulose under plasma treatment; (b). IR thermographic image for temperature distribution after 5 min. The temperature scale is shown in the right side bar.

(a)

(b)

Ar plasmaUntreated Air plasma

Fig S3. SEM images of the untreated and plasma-pretreated cellulose. The AC power condition

and pretreatment time are f = 17.5 kV, V = 2 kHz and t = 30 s for the Ar plasma-treated cellulose,

and f = 15 kV, V = 2 kHz and t = 30s for the air plasma-treated cellulose.

Fig S4. LC-MS results of the water-soluble fractions of the plasma pretreated cellulose. (a). the

Air plasma pretreated cellulose, (b). the Ar plasma pretreated cellulose. (Plasma pretreatment

conditions are f = 17.5 kV, V = 2 kHz and t = 30s for the Ar plasma, and f = 15 kV, V = 2 kHz

and t = 30 s for the air plasma.)

800130018002300280033003800

Untreated

Ar plasma

Air plasma

Wavenumbers [cm-1]

Fig S5. FTIR spectra of the untreated and plasma-pretreated cellulose. (Plasma pretreatment

conditions are f = 17.5 kV, V = 2 kHz and t = 30 s for the Ar plasma, and f = 15 kV, V=2 kHz and

t = 30 s for the air plasma.)

3320 3330 3340 3350 3360 3370 3380

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-0.5

0.0

0.5

1.0

Fresh4 hr9 hr12 hr

Magnetic field [G]

Rel

etiv

e In

tens

ity

Fig S6. EPR spectra of the air plasma-pretreated cellulose stored at ambient air for various times.

The “Fresh” sample was analyzed within 30 min after the plasma treatment. (Plasma pretreatment

conditions: f = 15 kV, V = 2 kHz, t = 30 s.)

0 4 8 12 1650

55

60

65

70

75

80

Storage time [hour]

LG y

ield

[wt%

]

Fig S7. LG yield produced from pyrolysis of the air plasma-pretreated cellulose stored at ambient

air for various times prior to pyrolysis. (Plasma pretreatment conditions: f = 15 kV, V = 2 kHz, t

= 30 s.)

3320 3330 3340 3350 3360 3370 3380

-4.0

-2.0

0.0

2.0

4.0

Cellulose

Cellobiose

Glucose

Magnetic field [G]

Inte

nsity

Fig S8. EPR spectra of the Ar plasma-pretreated cellulose and saccharides. (Plasma pretreatment

conditions: f = 17.5 kV, V = 2 kHz, t = 30 s.)