Scheme 1. Different routes for nitrile synthesis.

Fig. 1. Data characterizing the performance of various catalysts in ammoxidation of benzyl alcohol with various catalysts. Reaction conditions: 0.4 mmol of benzyl alcohol, 100 mg of catalyst, 100 μL of aqueous NH3 (28 wt%-30 wt%), 1.5 MPa of O2, 4 mL of t-amyl alcohol, 130 °C, 18 h. Conversions and yields were determined by GC analysis. More detail about the catalytic data are shown in Table S1.

Fig. 2. Conversion of benzyl alcohol and selectivity for benzonitrile and benzamide as a function of reaction temperature (a), ammonia amount (b), water amount (c), and catalyst amount (d) over α-Mn2O3-ca catalyst. Reaction conditions: 0.4 mmol of benzyl alcohol, 100 mg of catalyst, 1.5 MPa of O2, 4 mL of t-amyl alcohol, 18 h. More detailed data were shown in Tables S2-S4.

Fig. 3. Data characterizing the performance of various catalysts in benzonitrile hydration. Reaction conditions: 0.4 mmol of benzonitrile, 100 mg of catalyst, 75 μL of H2O, 1.5 MPa of N2, 4 mL of t-amyl alcohol, 130 °C, 18 h. Conversions and yields were determined by GC. More details were shown in Table S5. [a] 75 μL of D2O. [b] The data from Ref. [17], reaction conditions: 1 mmol of benzonitrile, Ru(OH)x/Al2O3 (4 mol% Ru), 3 mL of water, 140 °C.

Fig. 4. (a,b) Data characterizing the performance of various catalysts in benzonitrile hydration; (c) Conversion of benzonitrile as a function of α-Mn2O3 phase amount in the catalysts with different thermal treatments of β-MnO2. Reaction conditions: 0.4 mmol of benzonitrile, 100 mg of catalyst, 75 μL of H2O, 1.5 MPa of N2, 4 mL of t-amyl alcohol, 130 °C, 18 h. Conversions and yields were determined by GC. More details were shown in Tables S7 and S8. (d) Data characterizing the performance of various catalysts in ammoxidation of benzyl alcohol. Dependence of benzonitrile and benzamide yields on time over β-MnO2 (e) and α-Mn2O3(6h) (f) catalysts. Reaction conditions: 0.4 mmol of benzyl alcohol, 100 mg of catalyst, 100 μL of aqueous NH3 (28 wt%-30 wt%), 1.5 MPa of O2, 4 mL of t-amyl alcohol, 130 °C. Conversions and yields were determined by GC. More details were shown in Tables S9-S11.

Scheme 2. Catalytic selectivities of different catalysts in alcohol ammoxidation.

Fig. 5. (a-c) Conversion of different substrate as a function of time over the β-MnO2 and α-Mn2O3(6h) catalysts. Reaction conditions: (a,b) 20 mg of catalyst, 0.4 mmol of benzyl alcohol and benzaldehyde, 100 μL of aqueous NH3 (28 wt%-30 wt%), 4 mL of t-amyl alcohol, 1.5 MPa of O2 for (a), 1.5 MPa of N2 for (b), 130 °C. (c) 50 mg of catalyst, 0.4 mmol of benzonitrile, 100 μL of H2O, 4 mL of t-amyl alcohol, 1.5 MPa of N2, 130 °C. (d) Hammett plot for competitive hydration of benzonitrile and p-substituted benzonitrile derivatives over β-MnO2.

Fig. 6. In-situ FTIR spectra characterizing the H2O adsorption and H/D exchange over α-Mn2O3(6h) (a) and β-MnO2 (b). Line a in (a,b): catalyst was pretreated in flowing air at 200 °C for 2 h and purged in pure He at 200 °C for 1 h, the spectra were recorded at 150 °C. Line b in (a,b): Successively, at 150 °C, the catalyst was treated in 3 vol% H2O/He for 0.5 h, purged in pure He for 0.5 h, evacuated for 0.5 h, and treated in D2O for 10 min and the spectra were recorded. In-situ FTIR spectra characterizing the benzonitrile adsorption over α-Mn2O3(6h) (c) and β-MnO2 (d).