Partial and Total Solvent-Free Limonene’s Hydrogenation: Metals, Supports, Pressure, and Water Effects
Table 4
Hydrogenation of limonene over Rh.
Pressure (MPa)
Support
H2O
Conversion (%)
Menthene/menthane (%)
Cis/transmenthane (%)
Time (h)
TOF (h−1)a
Cymene (%)
2.75
Carbonb
—
100
0/100
45/55
2
75.5
4
100 µL
100
61/39
43/57
2
75.5
0
5 mL
100
79/21
49/51
2
75.5
2
—
100
0/100
49/51
5
30.2
0
100 µL
100
90/10
47/53
1
151.2
0
5 mL
70
100/0
—
6
17.6
0
0.275
Carbonb
—
100
88/12
49/51
6
25.2
5
100 µL
100
66/34
46/54
4
37.8
0
5 mL
65
82/18
32/68
24
4.1
9
—
92
100/0
—
3
46.4
5
100 µL
87
100/0
—
4
32.8
0
5 mL
41
82/13
31/69
24
2.6
18
Experimental conditions: pure limonene, the catalyst, and room temperature. aTurnover frequency (TOF) = number of moles of consumed limonene/(mole of catalyst) time of reaction; b5% wt.
