Hydrolysis of Methylhalides and Methylene Chloride

Methyl bromide gave comparable results with a conversion of 23% using a HaO/CHaBr ratio of 10 at 648 K with GHSV of 1000 cm g h.  

The authors subsequently examined the catalytic activities of the various catalysts comprised of 10 wt% metal oxide, 10 wt% aluminum hydroxide, and 80 wt% y-alumina, which were prepared by a water slurring procedure followed by calcination. As shown in Table, 4.23, the most effective catalyst was the ZnO/Al(OH)3/o -alumina system which gave 25% conversion. Nickel, bismuth, and magnesium hydroxides gave lower activity, as did other metal oxides when replacing zinc oxide. 

The hydrolysis of methylene chloride to formaldehyde was effected by heat-treated nickel sulfate or zinc sulfide.The reaction was suggested to occur through the abstraction of chloride ions from methylene chloride by the Lewis acid sites to form carbenium ions, CH2CI. 

Tanabe, in So/id Acids and Bases, Kodansha, Tokyo and Academic Press, New brk, 1970, p.l32. 

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