| 摘要 |
1357494 Dihydroxy platinum sulphurous acid; platinum sols PROTOTECH CO 17 May 1972 [16 June 1971] 23113/72 Heading C1A [Also in Divisions B1 and H1] The invention comprises an acid of the formula H 3 Pt(SO 3 ) 2 (OH) 2 . The said acid may be prepared by adding NaHSO 3 to an aq. soln. of Na 2 PtCl 6 until the pH is 4, and then adding Na 2 CO 3 to the soln. until the pH is 7 thereby forming a ppt. of Na 6 Pt(SO 3 ) 4 OH, slurrying the ppt. in water, adding ¢ mole of an acid resin, e.g. sulphonated styrene divinyl benzene in H form, per mole of Na 2 PtCl 6 , filtering the mixture and then passing the filtrate through an ion exchange column of the resin. Alternatively the said acid may be prepared by dissolving cold H 2 Pt(OH) 6 in aq. H 2 SO 3 of conc. 6% (w./v.) at a pH<7 and then boiling soln. to remove SO 2 . A colloidal sol. containing Pt having an average particle size in the range 15-25 Š may be prepared from the acid by heating the acid at a temp. of 135‹ C. for an hour and then dispersing the product in water. The Pt particles may be impregnated into C or a refractory and used as a catalyst (see Division B1). |
