Titan Atmospheric Chemistry Studies

Table 1: Titan Atmospheric Chemistry Simulation Experiments

Reference	Pressure	Initial Gas Mixture	Discharge	Temp	System	k-value at 0.5 mm	C/N	C/H	Chemical properties
Khare et al., 1984a	0.20 hPa	10% CH4, 90% N2	DC glow	300 K	flow	0.04	1.94a	0.6a	Less aliphatic C-H, amines, nitriles (IR) Aromatics and N heteroaromatics (Py-GC/MS)b 2-4 rings PAHs (L2MS)c
Khare et al., 1987	0.13 hPa	100% CH4	RF glow	300 K	flow	0.00108 - 0.00375		0.71d	Aliphatic C-H, (N-H or O-H due to leak?) (IR)
	0.13 hPa	7% CH4, 93%H2	RF glow	300 K	flow	0.0014 - 0.0027		0.66d
	0.13 hPa	3% CH4, 25%He, 72%H2	RF glow	300 K	flow	0.0044 - 0.035		0.57d	No CH, 1050 cm-1 (Si-O, glass contamination?) (IR)
McDonald et al.,1994	2 hPa	10% CH4, 90% N2	RF glow	300 K	flow		1.5e	0.6e	Aliphatic C-H, amines, nitrile, double bonds (IR)
	1 hPa	0.1% CH4, 99.9% N2	RF glow	300 K	flow		0.75	0.6	No nitriles, weak C-H, amines, double bonds (IR)
Coll et al., 1995	900 hPa	11% CH4, 89% N2	spark	~100 K	closedf		11	1
McKay, 1996	103 hPa	10% CH4, 90% N2	spark	300 K	flow		5.5	1
Coll et al., 1999	~2 hPa	2% CH4, 98% N2	DC glow	100 - 150 K	flow		2.8	0.8	Aliphatic C-H, amines, nitriles (IR)
									No aromatic except benzene (Py-GC/MS)
Ramirez et al., 2002	~1 hPa	2% CH4, 98% N2	DC glow	300 K	flow	0.0034
Khare et al., 2002	71 hPa	10% CH4, 90% N2	RF discharge	300 K	closedg				Aliphatic C-H, amine, nitrile double bonds, rings (IR)
Imanaka et al., 2004	0.13 hPa	10% CH4, 90% N2	RF glow	300 K	flow	0.031	1.45	0.75	No aliphatic C-H, amines, nitriles (IR), abundant aromaticsh
Imanaka et al., 2004	0.26 hPa	10% CH4, 90% N2	RF glow	300 K	flow	0.032	1.78	0.80	Less aliphatic C-H, amines, nitriles (IR), abundant aromaticsh
Imanaka et al., 2004	0.67 hPa	10% CH4, 90% N2	RF glow	300 K	flow	0.014	1.85	0.80	Aliphatic C-H, amines, nitriles (IR), abundant aromaticsh
Imanaka et al., 2004	1.6 hPa	10% CH4, 90% N2	RF glow	300 K	flow	0.0047	1.97	0.79	Aliphatic C-H, amines, nitriles (IR), less aromaticsh
Imanaka et al., 2004	23 hPa	10% CH4, 90% N2	RF glow	310 K	flow	0.0018	2.76	0.73	Aliphatic C-H, amines, nitriles (IR), much less aromaticsh

a Sagan et al., 1984

b Khare et al., 1984b; Ehrenfreund et al., 1995

c Sagan et al., 1993

d Elemental analysis (Khare, unpublished data)

e Data from Sagan et al. (1984)

f CH4 partial pressure maintained as 13 hPa

g Periodic supply of N2/CH4 for every 2 hr

h Abundance and size of aromatics are inferred from IR and UV/VIS spectroscopy, Raman spectroscopy, mL2MS

BACK NEXT