The “direct” synthesis of trialkoxysilanes: New data for understanding the processes of the copper-containing active sites formation during the activation of the initial silicon based contact mass

Effect of Copper Catalyst Content and Zinc Promoter on Carbon Formation in the Direct Synthesis of Methylchlorosilanes

“…The Zn promoted samples here demonstrate a higher initial Si consumption and higher reactivity than that of samples without Zn. The sharper rise in the reactivity curve during the first 5 h (Figure c-d) indicates that Zn in low quantities promotes the active phase formation . This is in agreement with the XRD analysis (Figure ), where samples promoted with Zn display relatively higher signal intensities for Cu 3 Si and lower intensities for Cu 15 Si 4 phases, as also proposed by Agarwala et al In the absence of Zn, more copper-rich phases, i.e., Cu 15 Si 4 , and metallic copper, are formed.…”

“…The sharper rise in the reactivity curve during the first 5 h (Figure 2c-d) indicates that Zn in low quantities promotes the active phase formation. 60 This is in agreement with the XRD analysis (Figure 4), where samples promoted with Zn display relatively higher signal intensities for Cu 3 Si and lower intensities for Cu 15 Si 4 phases, as also proposed by Agarwala et al 14 In the absence of Zn, more copper-rich phases, i.e., Cu 15 Si 4 , and metallic copper, are formed. Formation of flakes and cube shaped structures where Cu and Zn are associated, observed via SEM and elemental mapping analyses (Figures 4 and 5), also suggests the role of Zn to be dispersing Cu and promoting the active phase formation.…”

Bimetal chloride catalyzed hydrogenation of silicon tetrachloride in the presence of silicon

“…9(a) between 581 and 562eV were multi-peak fitted into three peaks with the Cu 0 , Cu + and Cu transition state. 27–30 The ratios of Cu 0 in the used Cu 10%–Ni 10% and Cu 10%–Co 10% catalysts were 34.3% and 37.4%, respectively, which are increased obviously compared with the monometallic chloride catalyst CuCl 20% (24.6%). It is known that both copper and silicon in metal copper and metal silicides are in the zero-valent state, suggesting that more metal silicides formed in the used catalysts.…”

Study of the Effect of Zn, Sn, and Pb Additives on the Direct Mechanochemical Synthesis of Tetramethoxysilane in the Presence of CuCl and CuO Catalysts

“…His works launched a study of the direct synthesis of alkoxysilanes (DSAlk), especially trialkoxysilanes, which are the “green” analogs of trichlorosilane, in the production of high-purity crystalline silicon for microelectronics . Over the past few decades, there have been a large body of publications devoted to the direct synthesis of trialkoxysilanes using various catalysts such as a Cu 2 O/CuCl mixture, CuCl, − abraded material from the brass milling bodies, , CuCl 2 , Cu­(OH) 2 , , and (CH 3 COO) 2 Cu . One of these works also compared CuCl, Cu­(OH) 2 , CuO, and CuSO 4 as copper sources for the preparation of triethoxysilane .…”