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Direct Synthesis of Methyl Chlorosilanes from Pd‐Mg‐SiO 2 Substrates Using Mechanochemistry
Author(s) -
Sparschu Wendy,
Larsen Robert,
Katsoulis Dimitris
Publication year - 2021
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.202000684
Subject(s) - chlorosilane , mechanochemistry , silicon , chemistry , palladium , ball mill , magnesium , selectivity , yield (engineering) , eutectic system , catalysis , inorganic chemistry , nuclear chemistry , organic chemistry , materials science , metallurgy , alloy
The direct reaction of methyl chloride with magnesium and palladium infused silica substrates to synthesize methyl chlorosilanes is reported. First, high energy ball milling on solid Mg‐SiO 2 mixtures produces elemental silicon and MgO. When PdCl 2 is infused into the mixture, after additional ball milling and high‐temperature reduction under H 2 , dipalladium silicide (Pd 2 Si) is produced. The silicon of the Pd 2 Si readily reacts with MeCl under Müller–Rochow reaction conditions, to produce methyl chlorosilanes at yield ratios analogous to those of the traditional process. The dominant product is Me 2 SiCl 2 (selectivity > 30%), followed by MeSiCl 3 and Me 3 SiCl, with minor amounts of the remaining chlorosilanes. Silicon conversion exceeds 20% for most of the substrates. The elemental palladium, which remains within the Pd‐Mg‐SiO 2 contact mass is re‐converted to Pd 2 Si at the next H 2 /high‐temperature treatment and reacts again with MeCl to repeat the methyl chlorosilane production. In principle, the resulting cycle of the mechanochemically induced formation of Pd 2 Si followed by the reaction with MeCl can be repeated until the starting SiO 2 converts completely to methyl chlorosilanes.