*3.3. Catalytic Activity Test*

A total of 0.1 mol MEK, 1.00 g catalyst, and 25 mL t-butanol were placed in a four-neck round bottom flask with a condensation reflux device. The constant temperature water bath was used to keep the temperature of the reaction system at 343K. NH3·H2O and H2O2 were slowly dropped into the flask for 1.5 h (MEK:NH3·H2O:H2O2 = 1:4:1.1), and then the reaction lasted for a certain period of time after the end of dropping. After the reaction, the catalysts were filtrated and separated. The content of MEK (standard curve method) was detected by high performance liquid chromatography (HPLC). The content of MEKO (standard curve method) was detected by gas chromatography (GC) after the filtrate was volumed with absolute ethanol.

The 3 wt % Ni-TS-1 catalyst was reused. The catalyst, for the first reaction, was completely transferred to the second reaction, and so on. The catalyst was reused for five times with other conditions unchanged. In addition, the catalyst that was reused five times was calcined (540 ◦C for 7 h) to activate and regenerate, and applied to the ammoximation of MEK again.

$$\text{Conversion of MEK} \left( \% \right) = \frac{\text{Converted moles of MEK}}{\text{Initial moles of MEK}} \times 100\% \tag{1}$$

$$\text{Selocity of MEKO } (\%) = \frac{\text{Moles of MEKO}}{\text{Corrected moles of MEK}} \times 100\%. \tag{2}$$

Liquid chromatography conditions: Shimadzu HPLC LC-20AT; the column is Diamons C18 column (250 mm × 4.6 mm, 5 μm), the UV detection wavelength is 274 nm, the mobile phase is V methanol:V water = 50:50, and the flow rate is 0.8 mL/min.

Gas chromatographic conditions: Shimadzu gas chromatograph GC-2010; the column is FFAP capillary column, the carrier gas is high purity nitrogen, the inlet and the detection port temperature is 200 ◦C, and the column temperature is 100 ◦C.
