III International Conference

PP-I-12EFFECT OF THE HYDROGEN PEROXIDE OXIDATION OF CARBON SUPPORTOF ZINC ACETATE CATALYST FOR ACETYLENE HYDROACETOXYLATIONBong H.K., Kurlyandskaya I.I., Hoang Huu Binh,Glazunova E.D., Volkov V.V., Obolonkova E.C., Temkin O.N.Moscow State Academy of Fine Chemical Technology named after M.V. LomonosovE-mail:hoang46@mail.ruThe main problem of an efficient Zn(CH 3 COO) 2 /AC (AC-activated carbon) catalystpreparation is the achievement of uniform distribution of finely dispersed rather active duringcatalysis salt component (SC) immobilized on support surface. We have found the decision ofthis task in liquid phase oxidation of activated carbon with nitric acid or hydrogen peroxide,in the mode of salt application [1, 2] and catalyst drying.The objective of the present investigation is to study the characteristic changes of supportsample AC AGN- 2 the initial (S1) one and oxidized with hydrogen peroxide (H 2 O 2 ) (S2) aswell as of the catalysts (C1) and (C2) on support (S1) and (S2), correspondingly underconventional drying at T= 150°C and (C3) on support (S2) under slow drying (0,3°C⋅min -1 ).For this purpose the adsorption method has been used (adsorption of benzene vapours,water, acetic acid and zinc acetate adsorption from aqueous solution). Particular distributionof zinc acetate on AC surface of C1, C2, C3 has been studied by small-angle X-ray scattering(SAXS), scanning electron microscopy (SEM) and by X-ray microanalysis (XMA).The catalysts were tested during the vinylacetate synthesis reaction in flow isothermalreactor by cycle method at 175, 205 and 230 o C [3].When oxidized with H 2 O 2 AC changes it texture sufficiently. Thus specific surface of S2sample as compared with S1 increases by 50 m 2·g -1 as much as 920 m 2·g -1 , the micro-andmesopores share in S2 clearly getting greater (fig. 1). The increase of available adsorptionsites number as for described above texture changes and transformation of surface oxygenfunctional groups on AC (S2) result in increase of both adsorption capacity and differentialheat adsorption both for polar (H 2 O, CH 3 COOH) and non-polar (C 6 H 6 ) substances, despitetheir different adsorption mechanism. It was found that the maximum amount of adsorbedspecies at P/P s =0,8 as for benzene increased by 14 % and as for water by 36 %.Simultaneously a significant increase (approximately 3 times) the adsorption capacity of zincacetate as for S2 as compared with S1 was observed.29