Pd–Au (75 : 25) nano colloid was prepared by using various reductants and it was found that the mono dispersed Pd–Au nano colloid with 4.7 nm in diameter was prepared by reduction with oxalic acid and this Pd–Au nano colloid is highly active for the synthesis of H2O2 by direct oxidation of H2 with O2. The yield of H2O2 increased with increasing reaction pressure and at 1 MPa, H2O2 yield achieved a value of 30%. Under these conditions, H2 conversion is as high as 80%. H2O2 yield was further improved by increasing H2 partial pressure, and the optimum H2 partial pressure was 10% at 1 MPa because of safety (out of the explosion limit concentration in reactor) and the formation rate of H2O2. Because H2O2 decomposition is prevented, H2O2 yield also increased with decreasing reaction temperature and at 268 K, H2O2 yield and production rate are achieved as high as 46% and 25 mmol h−1, respectively, in aqueous solution. H2O2 concentration reaches a value of 5.8% in aqueous solution after 20 h at 268 K.
You have access to this article
Please wait while we load your content...
Something went wrong. Try again?