React. Kinet. Catal. Lett., Vol. 48, No. 2, 455-460 (1992) RKCL2077 Li/MgO CATALYSTS. III. EFFECT OF PRECURSOR SALTS ON THE CATALYTIC ACTIVITY IN METHANE OXIDATIVE COUPLING M.J. Holgado, V. Rives + and S. San Roman Departamento de Quimica Inorg~nica, Universidad de Salamanca; Facultad de Farmacia, Avda. Campo Charro, s/n, 37007-Salamanca, Spain Received June 3, 1992 Accepted September 28, 1992 Oxidative coupling of methane has been studied on Li/MgO catalysts prepared from three different MgO precursors and from lithium carbonate or nitrate. In samples prepared from Li2C03, the persistence of this on the support surface favors formation of carbon ox- ides. ~eaKHHH OKHC~HTe~bHOFO cOe~HHeHH~ MCTaHa HccMe~oBa~H Ha KaTanH3aTopax Li/MgO, HpHFOTOB~eHHbIX H9 TpeX pa3nHqHblX Hpe~meCTBeHHHKOB MgO H Kap@OHaTa HaH HHTpaTa ~HTHS. B 06- pa3Hax, HpHFOTOB~eHHMX HS Li2C03, OCTaTKH nocne~HeFo Ha HOBepXHOCTH HOCHTenS 6naFOHpHSTCTBymT o0pa3OBaHHm OKHC- nOB yPnepo~a. INTRODUCTION We have previously reported on the preparation and charac- terization of Li/MgO catalysts prepared from commercial MgO, Mg5(OH)2(CO3)4.4H20 and magnesium nitrate, and from lithium carbonate or nitrate [i, 2]. It has been shown that the nature of the precursor salts (mainly those of lithium) plays an im- portant role in both the nature of the species existing on the catalyst surface, and on the specific surface area development. We now report on the activity of these samples in methane oxi- Akad6miai Kiad6, Budapest