Plasma surface modification of zeolites with gas phase ciagnostics

Gas Phase Studies

Plasma Surface Modification of Zeolites with Gas Phase Diagnostics

Angela R. Hanna and Ellen R. Fisher

Department of Chemistry, Colorado State University

Substrate Studies

Time (s) I N x O y /I Ar Formation & destruction mechanisms Wavelength (nm) 200 220 240 260 280 300 320 340 360 E m issi on (a. u.) Energy Partitioning Oxygen Water (vapor)

“Solving these challenges requires developing an understanding

of the fundamental plasma–surface interactions in an integrated

approach that combines new computational strategies and

diagnostic techniques

.” – 2017 Plasma Roadmap

Nitrogen

Conversion to

green species

Substrate Selection

Gas - Surface

Interface

Substrate Plasma

Gas Phase Studies

Future

Directions

Plasma bulk

Surface

Plasma Surface Interface

_{Fisher Research Group}

Dr. Ellen Fisher

Gary E. Maciel Fund

Acknowledgments

The atomic composition & morphology of Pt foil remained unchanged after N₂O plasma exposure. Applied rf Power (W) 100 150 200 T R (K) 400 600 800 1000 Pt foil Si wafer No substrate Zeolite

Catalytic substrates appear to result in higher T_V(NO) at

higher plasma powers.

Presence of catalytic substrate does not dramatically affect rotational cooling pathways

Wavelength (nm) 200 220 240 260 280 300 320 340 360 Em iss ion (a .u .) Experiment Simulation Wavelength (nm) 220 240 260 280 300 320 340 360 A b so rb an ce (a .u .) Experiment Simulation NO N₂ T_R 500 K 305 K T_V 4000 K 5100 K NO N₂ T_R 600 K 310 K T_V 4300 K 4350 K Applied rf Power (W) 50 100 150 200 T V (K ) 3000 3500 4000 4500 5000 5500 N2 (C 3_ u) NO (A2) N₂ (B3_g) NO (X2) Applied rf Power (W) 100 150 200 T V (K) 3500 4000 4500 5000 5500 6000 6500 Pt Foil Si Wafer No substrate Zeolite Pellet Applied rf Power (W) 50 100 150 200 S (N O) 0.0 0.4 0.8 1.2 1.6 2.0 Si substrate Pt substrate

Can we tailor the surface

features of materials for

catalysis applications?

What do temporally- and

spatially-resolved spectroscopy data reveal about

underlying plasma phenomena?

How does the morphology of a

substrate influence steady-state

surface coefficients?

Zeolite Pellet Native Zeolite

Platinum Foil

Zeolite Pellet

C

₂

F

₆

Plasma Treated

-

₌

Beam + Scatter Subs tra te Subs tra te

Incident Beam Only Scatter

a) b) c)

Steady State Energetics

Surface Scatter

Spectroscopy with Substrates

Zeolites

Flat

Constructs

Porous Materials

Untreated

NO Plasma Treated

Porous morphology is maintained

H

₂

O Plasma Treated

Assess surface modification of high surface area materials with a

depositing precursor.

Top of pellet shows FC film formation, while porous morphology is present at edge

Zeolite Pellet Native Zeolite Zeolite Pellet

O 53.9 ± 0.04% Si 18.2 ± 0.02% C 22.4 ± 0.01% Al 5.5 ± 0.04% 100 μm 10 μm 10 μm 1 μm 1 μm 1 μm 1 mm 1 mm 1 μm Si _2p O 59.9 ± 1.2% Si 22.3 ± 0.12% C 11.8 ± 1.3% Al 6.0 ± 0.03%