Removal of organometallic compounds from natural feedstock by surface organometallic chemistry on metals: hydrogenolysis of AsPh3 on nickel supportedon alumina

Hydrogenolysis of triphenylarsine (AsPh3) on Ni/Al2O3 at 172 degreesC and 6 bars of hydrogen occurs selectively on the nickel particles and not on the alumina support. According to the kinetic, magnetic and XRD data, the reac tion of AsPh3 with the surface Ni-s-H produces benzene and the surface orga nometallic fragments Ni-s-[AsPhx](y). Stepwise hydrogenolyis of these fragm ents leads progressively, with time, to the formation of arsenic 'adatoms', which migrate rapidly inside the nickel particles. The reaction is stopped after complete formation of a well defined Ni-As alloy, which has beep ful ly characterized by X-ray diffraction. (C) 2000 Academie des sciences / Edi tions scientifiques et medicales Elsevier SAS.