摘要 |
A method for the selective production of acetic acid from a gas-phase feed of ethane, ethylene, or mixtures thereof and oxygen at elevated temperatures. The gas-phase feed is brought into contact with a catalyst, containing the elements Mo, Pd, X and Y in the gram atom ratios a:b:c: in combination with oxygen according to formula (I): MO<SUB>a</SUB>Pd<SUB>b</SUB>X<SUB>c</SUB>Y<SUB>d</SUB>. The symbols X and Y have the following meanings: X=one or several elements chosen from the group Cr, Mn, Nb, Ta, Ti, V, Te and W; Y=one or several elements chosen from the group B, Al, Ga, In, Pt, Zn, Cd, Bi, Ce, Co, Rh, Ir, Cu, Ag, Au, Fe, Fu, Os, K, Rb, Cs, Mg, Ca, Sr, Ba, Nb, Zr, Hf, Ni, P, Pb, Sb, Si, Sn, Ti and U: the indices a, b, c, d and x=the gram atom ration for the corresponding elements, where: a=1; b-0.0001 to 0.01; c=0.4 to 1; and d=0.005 to 1, wherein the space-time yield for the above oxidation to yield acetic acid is 470 kg/(hm<SUP>3</SUP>) and the selectivity of the oxidative reaction of ethane and/or ethylene to give acetic acid is, in particular, >=70 mol %. X=preferably Nb and an ammonium salt of niobium is used as niobium source. |