Total: 10 pages, 4 figures and 4 tables.

Transcription

1 Supporting Information Catalysis in flow: Nickel-catalyzed synthesis of primary amines from alcohols and NH 3 Andrew Yuk Keung Leung, Klaus Hellgardt and Mimi (King Kuok) Hii Total: 10 pages, 4 figures and 4 tables. S1 Flow reactor set up -Page S2 S2 Residence time calculations -Page S3 S3 Preliminary experiments with commercial catalysts and compare with other papers -Page S4 S4 Temperature study with improved batch system using anhydrous ammonia -Page S5 S5 TOF calculations S6 Time course for BnOH amination with ammonia in flow S7 Catalyst characterisation -Page S6 -Page S7 -Page S8 Figures Figure S1. Catalyst pre-reduction/activation in situ set-up Figure S2. Time course for BnOH amination with ammonia in flow. Figure S3. TEM images of 65 wt% Ni-Al 2 O 3 /SiO 2. Graph showing catalyst particle size distribution Figure S4. XRD spectra for comparison of catalysts at different stages. Tables Table S1. List of commercial catalysts and their catalytic performance. Table S2. Results from reactions using the batch reactor under different temperatures. Table S3. TOF of flow reactions Table S4. Ni catalyst at different stages and their BET & TPD results S1

2 S1 Flow reactor set up Figure. S1. Catalyst pre-reduction/activation in situ set-up The heated reactor consists of a SS316 ¼ tube (22 cm) containing 2.0 g of extruded catalyst (36%wt Ni) supported by quartz wool. The temperature was controlled by a West 6400 controller. The catalyst was treated under 5% H 2 /He flow (40 ml/min) for 2 hours at 500 C prior to reaction. (Fig. S1). Once the reactor had cooled to room temperature, it was reconfigured to allow liquid flow (Fig. 1 in paper). S2

3 S2 Residence time calculations The residence time (t R ) can be calculated according to eq. 1 = (Eq. 1) Where V d is the dead volume within a packed cartridge, and v is the applied flow rate. The voidage ( ) is the ratio of the dead volume ( ) and the total inner volume ( ) of the reactor, as shown in eq. 2 = (Eq. 2) Combining the first two equations, we can get the equation for residence time to get eq. 3 = (Eq. 3) Total internal volume (V tot ) = 22 cm x area of ID of 1/4 SS tubing 1/4 OD = 0.25, Wall thickness = ID = ( ) x2 = 0.18 = 0.46 cm Internal volume = 22 (. ) = Wetted packed bed in tube Dry packed bed in tube O-xylene mass O-xylene density Void volume = g = g = g = 0.88 g/ml = 2.8 ml Thus, at a flow rate of 0.5 ml/min, residence time (τ) = 5.6 mins S3

4 S3 Preliminary experiments with commercial catalysts and compare with other papers Table S1. List of commercial catalysts and their catalytic performance. Catalyst Conv. Sel. Source RNH 2 R 2 NH R 3 N 1 a a 65 wt% Ni/Al 2 O 3 /SiO 2 44% 85% 15% 0% Sigma 2 a 16 wt% Ni/Al 2 O 3 /CaO 20% 96% 0% 0% Alfa Aesar 3 a 16 wt% NiMo/Al 2 O 3 10% 0% 0% 0% Prepared 1 4 b b 1 wt% Au/TiO 2 48% 0% 60% 37% Strem 5 b b 1 wt% Ru/Al 2 O 3 29% 0% 12% 63% Sigma 6 b 1 wt% Pt/Al 2 O 3 16% 12% 32% 36% Sigma Conditions: BnOH/NH 3 /H 2 O = 1/1/ a ROH/Ni = 20, b ROH/M = 100 S4

5 S4 Temperature study with improved batch system using anhydrous ammonia Table S2. Results from reactions using the batch reactor under different temperatures. 24 hours 72 hours Entry Temperature Conversion Selectivity Conversion Selectivity ( C) % nil 5% 100% % 93% 60% 93% % 96% 96% 97% Conditions: Alcohol (0.1 M) in o-xylene, extruded 36wt% Ni-Al 2 O 3 /SiO 2, BnOH/Ni = 10, BnOH/NH 3 = 7, 1000 rpm, 4.6 bar (25 C) S5

6 S5 TOF calculations = ( ) ( ) (eqn. 4) Where mmol active sites were determined by the BET & TPD analyses (see S6) Table S3. TOF of flow reactions Flow rates (ml/min) Conv. Sel. TOF (min -1 ) %±1.7% 100% 0.044± %±2.2% 100% 0.060± %±.3.1% 100% 0.049± %±0.9% 97%±1.2% 0.048± %±0.9% 100% 0.026± %±0.7% 100%±0.8% 0.017± Conditions: Flow reactor, 0.10 M BnOH in o-xylene, NH 3 /BnOH = 7, 2.0 g extruded Ni- Al 2 O 3 /SiO 2 S6

7 S6 Time course for BnOH amination with ammonia in flow (Table 2, entry 1) Figure S2. Time course for BnOH amination with ammonia in flow. Conditions: 0.10 M BnOH in o-xylene, NH 3 /BnOH = 7, 2.0 g extruded 36wt% Ni-Al 2 O 3 /SiO 2, 0.06 ml/min, residence time (τ) = 46.7 min; S7

8 S7 Catalyst characterisation Methods: BET: N 2 adsorption was carried out with a Micromeritics 3Flex surface characterisation analyser. The Brunauer-Emmett-Teller (BET) method was used to calculate the specific surface areas, pore volumes and diameters. TPD: Temperature Programmed Desorption was carried out with a HY-800 heater unit with a West 9400 temperature controller g of samples were loaded into a ¼ quartz tube supported by quartz wool, subsequently dried at 500 ⁰C under He flow (30 ml/min) for 1 hour, followed by soaking in probe gas for 1 hour at 50 ⁰C, and then heated at 100 ⁰C to remove physisorbed probe gas. Sample was subsequently heated to 750 ⁰C at 5⁰C/min and desorption of probe gases were measured with a Fisons VG Quadrupoles Mass-Spectrometer. Probe gases were 5% NH 3 /He and 10% CO 2 /He for acidic and basic sites respectively. ICP-OES: Elemental analysis was carried out with a PerkinElmer Optima 2000DV Inductively Coupled Plasma instrument. Sample prep. 5 ml liquid samples were concentrated under vacuo at 70⁰C for 15 mins, then digested by aqua regia (0.4 ml); solid samples (~2 mg) were digested in aqua regia (2 ml) at 90 ⁰C for 16 hours. Samples were then diluted 50x with DI water; TEM: Transmission Electron Microscopy was measured with JEOL JEM-2100F TEM operated at 200 kv. XRD: Powdered X-ray diffraction was measured with a PANalytical X pert Pro X-ray diffractometer, using CuK α radiation (α = Å) from 2θ = 10⁰ to 70⁰ with 0.02⁰ increments. Table S4: Ni catalyst at different stages and their BET & TPD results BET TPD Sample S BET (m 2 /g) Average pore volume (cm 3 /g) d p.avg (nm) Basicity (µmol/m 2 ) Acidity (µmol/m 2 ) Catalyst a ± Bentonite nil Extrusion b ± ±0.2 Extrusion after reaction a Catalyst = 65wt% Ni/Al 2 O 3 /SiO 2, b extrusion = 60% (Catalyst) + 40% (Bentonite); c averaged over 5 different samples. S8

9 TEM The TEM images suggest that the particles are amorphous. The particle sizes were determined over 182 particles over different images. The mean particle size was 4.66 nm. This was confirmed by XRD particle size estimations. Particle size distribution 60 Counts Size (nm) Figure S3. TEM images of 65 wt% Ni-Al2O3/SiO2. Graph showing catalyst particle size distribution S9

10 Intensity/a.u. Mt SiO Mt Ni (111) Spent Extrusion Bentonite Commercial XRD θ/Degrees Figure S4. XRD spectra for comparison of catalysts at different stages. Mt 2 represents montmorillonite Particle sizes were estimated with the Scherrer equation, D=Kλ/βcosθ Using the Ni (111) peak, a grain size of 4.2 nm was estimated. This matches with the TEM results of average 4.66 nm. NMR Benzyl amine 2 1 H NMR (300 MHz, CDCl 3 ): δ = 1.55 (s, 2H), 3.90 (s, 2H), 7.33 (m, 5H). 13 C δ = , , , 77.40, ppm 3 GC-MS (EI) Benzyl amine: m/z (%): 106 (100), 91(18), 79(39), 55(9) 2-Phenyl ethylamine: m/z (%): 121(50), 103(8), 91(100), 77(18), 65(52), 51(30) 2-Aminomethyl pyridine (2-picolyl amine) m/z: 106(82), 92(8), 79(100), 65(7), 52(30) 3-Aminomethyl pyridine (3-picolyl amine) m/z: 107(24), 92(7), 79(100), 65(7), 52(10) Octan-2-amine: m/z: 128(2), 114(4), 84(2), 72(6), 56(10), 44(100) 2-methoxybenzyl amine: m/z: 136(100), 121(48), 106(52), 91(50), 77(50), 65(30), 51(25) 3-methoxybenzyl amine: m/z: 136(100), 121(18), 106(40), 91(28), 77(30), 65(18), 51(10) References (1) Purón, H.; Pinilla, J. L.; Berrueco, C.; Montoya de la Fuente, J. A.; Millán, M. Energy Fuels 2013, 27, (2) Saavedra, J. Z.; Resendez, A.; Rovira, A.; Eagon, S.; Haddenham, D.; Singaram, B. J. Org. Chem. 2012, 77, 221. (3) Ji, P.; Manna, K.; Lin, Z.; Feng, X.; Urban, A.; Song, Y.; Lin, W. J. Am. Chem. Soc. 2017, 139, S10