(FR2670400-A1)      Prepn. of multi-metallic catalysts, the active phase comprising two metals, A and B, belonging to gps. VIII and IB, on a porous support, is carried out in four stages:- (1) at least one part of the support is impregnated with at least one precursor of the metal A; (2) activation is effected in a neutral or oxidising atmos. at 120-800 deg. C; (3) the support is then impregnated with at least one precursor of metal B and (4) activation is carried out in a neutral or oxidising atmos. at 120-800 deg. C. The activation at the second step is followed by a treatment in a reducing medium at 0-800 deg. C.    USE/ADVANTAGE -   The multi-metallic catalysts are frequently used in refining petrochemical and fire chemical industries and combustion or post-combustion processes. They usually have a better selectivity than mono-metallic catalysts and are more stable partic. at high temps.. When used in post-combustion applications (such as conversion of exhaust gases from internal combustion engines) metal A is Pt or Pd and metal B is Pt, Pd or Rh (B is different from A)    (JP5505764-W)      Prepn. of multi-metallic catalysts, the active phase comprising two metals A and B belonging to gps. VIII and IB, on a porous support, is carried out in four stages: (1) at last one part of the support is impregnated with at least one precursor of the metal A; (2) activation is effected in a neutral or oxidising atmos. at 120-180 deg.C; (3) the support is then impregnated with at least one precursor of metal B; and (4) activation is carried out in a neutral or oxidising atmos. at 120-800 deg.C. The activation at the second step is followed by a treatment in a reducing medium at 0-800 deg.C.    USE/ADVANTAGE -   The multi-metallic catalysts are frequently used in refining petrochemical and fine chemical industries, and combustion or post-combustion processes. They usually have a better selectivity than mono-metallic catalysts and are more stable partic. at high temps.. When used in post-combustion applications (such as conversion of exhaust gases from internal combustion engines) metal A is Pr or Pd and metal B is Pr, Pd or Rh (B is different from A).    (US5413984-A)      Multimetal catalyst is produced in which the active phase comprises at least two metals A and B of gps. VIII and IB, deposited on porous carrier. Method comprises (1) impregnating (part of) the carrier with at least one precursor and (A); (2) actuating prod. in neutral or oxidising atmos.; (3) impregnating (part of) the carrier already impregnated with precursor of (A) with precursor of (B); and (4) activating prod. in neutral or oxidising atmos..    The improving is that after stage (2) the prod. is treated in reducing medium at 0-800 deg.C.    USE/ADVANTAGE -   In catalytic reforming of hydrocarbons. Method increases stability of catalytic performance.