Table 2. Reaction Condition Optimization for the Reduction of Nitrobenzene to Aniline with Formic Acida.
| entry | catalyst | catalyst loading (mol %) | solvent | temperature (°C) | conversion (%)b | selectivity (%)b |
|---|---|---|---|---|---|---|
| 1 | 0 | 2-PrOH/H2O (9/1) | 150 | 20.2 | 2.5 | |
| 2c | UiO-66 | 2-PrOH/H2O (9/1) | 150 | 28.5 | 2.8 | |
| 3 | RuCl3 | 1.0 | 2-PrOH/H2O (9/1) | 150 | 28.2 | 1.8 |
| 4 | UiO-66–Ru | 1.0 | 2-PrOH/H2O (9/1) | 150 | 100 | >99 |
| 5 | UiO-66–Ru | 0.5 | 2-PrOH/H2O (9/1) | 150 | 100 | 42.8 |
| 6 | UiO-66–Ru | 0.7 | 2-PrOH/H2O (9/1) | 150 | 100 | 89.6 |
| 7 | UiO-66–Ru | 1.0 | 2-PrOH/H2O (9/1) | 110 | 60.2 | 54.0 |
| 8 | UiO-66–Ru | 1.0 | 2-PrOH/H2O (9/1) | 130 | 66.9 | 75.3 |
| 9 | UiO-66–Ru | 1.0 | 2-PrOH | 150 | 62.8 | 39.4 |
| 10 | UiO-66–Ru | 1.0 | 2-PrOH/H2O (4/1) | 150 | 72.4 | 34.1 |
| 11 | UiO-66–Ru | 1.0 | EtOH | 150 | 91.0 | 12.7 |
| 12 | UiO-66–Ru | 1.0 | MeOH/H2O (4.5/1) | 150 | 90.8 | 59.8 |
| 13 | UiO-66–Ru | 1.0 | toluene | 150 | 84.1 | 95.0 |
a
Reaction conditions: nitrobenzene 0.5 mmol, formic acid 2.5 mmol, solvent 3 mL, reaction temperature 150 °C, reaction time 3 h.
b
Conversation and selectivity were determined by GC on the basis of area %.
c
UiO-66 17.0 mg.