Ruthenium chloride prodn. from sodium hexa:chloro ruthenate - by fractional dissolution in alcohol, useful for making sugar hydrogenation catalysts

摘要

Prodn. of RuCl3 comprises first preparing Na2RuCl6 (I) by reacting, at 600-650 deg.C, a powdered mixt. of Ru and NaCl with chlorine generated by pyrolysis of CCl4. (I) is then fractionally dissolved in absolute alcohol to recover, after filtering off suspended NaCl, a soln. of RuCl3. This soln. is then evaporated. Also new is a catalyst (A) for heterogeneous hydrogenation of sugars to alcohols, made by impregnating a carrier, esp. silica, with an aq. soln. of RuCl3, then drying and reducing. (A) are used to prepare sorbitol, mannitol and xylitol from, respectively, glucose, mannose and xylose. These alcohols, esp. sorbitol, are useful in pastry-making nad pharmacy. (A) provide a more complete and esp. more rapid hydrogenation than conventionally prepd. catalysts.