No abstract

SiHCl3 (TCS) and SiCl4 (STC), important chlorosilanes in the silicon industry, are currently produced by noncatalytic silicon hydrochlorination with a selectivity of 85% for TCS and 15% for STC approximately. It is a significant challenge to selectively produce TCS and STC with the desired ratio in one reactor to realize flexible manufacturing that meets the periodic market demands. In the present work, we develop a novel Ni-Ni3P/SiO2 catalyst using a simple reduction synthesis method to produce STC selectively in Si hydrochlorination. The catalyst performance is evaluated under different industrial operating conditions. It shows that the Ni-Ni3P/SiO2 catalyst exhibits a selectivity higher than 90% for STC and a selectivity of <10% for TCS under the optimal conditions. The calculations based on the density functional theory show that P-modified Ni-based catalysts promote the breakage of HCl bonds and make the product favor STC instead of TCS. Therefore, it is possible to realize flexible manufacture of TCS and STC in one reactor by combining the CuO-based catalysts reported in our previous work to enhance TCS production and the Ni-Ni3P/SiO2 catalyst developed in this work to promote STC production.

Structure D 2000Structures of ζ and ζ' Phases in the Ag-Ga System. -As revealed by Rietveld refinement of powder XRD data the ζ' phase of the title system (Ag2+xGa1-x, x = 0.16) crystallizes in the space group P62m with Z = 3. The ζ-phase crystallizes in the close-packed hexagonal space group P63/mmc with Z = 2. -(ZHANG, Y.; LIU, Q. L.; LI, J. B.; LIANG*, J. K.; LUO, J.; LIU, F. S.; XIAO, Y. G.; RAO, G. H.; J. Alloys Compd. 399 (2005) 1-2, 155-159; Inst. Phys., Chin. Acad. Sci.,