| 摘要 |
Catalyst is regenerated to recover its selectivity by contacting it with an oxygen excess above 0.35 mole/mole of the cpd. to be oxidised (I) over the stoichiometric amt. for a period sufficient to regain or approach the original selectivity. Oxygen in air is used or a mixt. with (I) in molar ratio 4/1 (pref. 1.35/1-1.5/1). Regeneration takes 1-3 days. Catalyst e.g. for oxidising ethylene glycol to glyoxal may be Cu activated by Gp. Vb elements (Ge, Sn, Pb) and/or Gp. Vb elements (N, P, As), e.g. Cu/P contg. 2-4% P. |
