The date of Mo1Sn20

The evaluation process of methanol oxidation to methylal reaction is carried out on an atmospheric pressure continuous flow fixed bed reactor. During the experiment, a 1.5 mL ceramic ring (20-40 mesh) was used to dilute 0.5 mL (20-40 mesh) of catalyst. Before the reaction, the reaction tube is programmed to heat up and the catalyst is pre-treated with oxygen. When the temperature rises to 300 ° C, the catalyst is activated by maintaining a constant temperature in an oxygen atmosphere for 2 hours. Afterwards, it is cooled to a reaction temperature of 140 ° C and methanol is slowly introduced. The ratio of methanol to oxygen during the reaction process is 1:9.415 (molar ratio), with a volumetric space velocity of 7200 h-1, and the flow rate of the exhaust gas is detected. X-ray diffraction (XRD) testing was conducted on the MiniFlex 600 X-ray diffractometer from Rigaku Corporation in Japan, using Cu K α Radiation irradiation, with a scanning angle of 5-90 ° and a continuous scanning rate of 4 °/min. The programmed temperature desorption (NH3-TPD) test was conducted on the TP 5080 chemical adsorption instrument. Weigh 100 mg of catalyst and place it in a sample tube. Heat it up to 400 ° C in an inert atmosphere with a gas flow rate of 30 mL/min, then cool it down to 50 ° C. Introduce NH3 (30 mL/min) for adsorption for 10 minutes, then blow it out. Finally, heat it up to 600 ° C for desorption and record the signal. The programmed temperature reduction (H2-TPR) test was conducted on the TP 5080 chemical adsorption instrument. Weigh 100 mg of catalyst and place it in a sample tube, program the temperature to 200 ° C, and then cool it down to 50 ° C. Then, the mixed gas is introduced and the temperature is programmed to 900 ° C to reduce the catalyst, and the signal is recorded. The N2 physical adsorption and desorption test was conducted on a Japanese Bayer (BEL) BELSORP-MAX II instrument, and the catalyst sample was subjected to degassing pretreatment at 200 ° C. Then, a low-temperature N2 adsorption and desorption experiment was conducted using pure liquid nitrogen as the adsorption medium (-196 ° C). Raman testing was conducted on a Horiba evolution Raman spectrometer, with an excitation wavelength of 532 nm and a scanning range of 100-1100 cm-1. Fourier transform infrared spectroscopy (FT-IR) was performed on Bruker Tensor 27, using KBr to scan the background. Place the catalyst into the sample cell, with Ar as the carrier gas, raise the temperature to 200 ° C, maintain the temperature for 1 hour, and then lower it to the test temperature for testing. X-ray photoelectron spectroscopy (XPS) characterization was performed on Thermo Fisher's ESCALAB 250xi X-ray photoelectron spectroscopy, with a particle source of A1 K α (hv=1486.6 eV), use the binding energy of C1s (284.6 eV) to compare and correct with the measured element.