MODIFICATION OF THE ACTIVITY OF MG-3(PO4)(2) IN THE GAS-PHASE CONVERSION OF CYCLOHEXANOL BY ADDITION OF SODIUM-CARBONATE

This paper reports the synthesis and characterization of solid NaMgPO4, obtained by adding Na2CO3 to freshly formed Mg-3(PO4)(2).22H(2)O. The magnesium orthophosphate was prepared by gelling an aqueous solution of MgCl2 and Na2HPO4 with 3 N NaOH. The solid products thus obtained were characterized by using various structural (XRD), surface (XPS, DRIFT, BET), and morphological (SEM) elucidation techniques. The results show that the NaMgPO4 surface also contains Na2CO3, NaCl, and MgO, which endow it with increased activity and selectivity. Thus, Mg-3(PO4)(2) yields cyclohexene (CHE) preferentially, and some cyclohexanone (CHONE), in the gas-phase conversion of cyclohexanol. On the other hand, NaMgPO4 produces CHONE selectively under the same reaction conditions. (C) 1995 Academic Press, Inc.