Experimental Study on Hydrogenation of SiCl_4 to SiHCl_3 in a Stirred Bed Reactor

The hydrogenation of SiCl4 to SiHCl3 was studied in a stirred bed reactor with CuCl catalyst. The properties of the CuCl catalysts and silicon particles before and after the reaction were characterized by SEM, XRD and XPS. The XRD showed that the active component of Cu3Si was formed during the reaction, and the EDX proved the molar ratio of Cu and Si on the region of apertures. The valent of Cu was discussed by XPS before and after the hydrogen reaction. Then the effects of the reaction temperature, pressure, molar ratio of H2 to SiCl4, weight hourly space velocity (WHSV), and catalyst loading were studied. The results showed that the conversion rate of SiCl4 was about 38% at WHSV of 190 Nm3/(t?h), temperature of 540℃, pressure of 1.8 MPa, catalyst loading of 0.9%(?), and molar ratio of H2 to SiCl4 1.7:1. Based on the experemental results, a reaction mechanism was proposed, which involved the continuous consumption of silicon (many apertures was showed on SEM image) and formation of new Cu3Si active component during the hydrogenation reaction.