Hydrogenation and ring opening of naphthalene on bulk and supported Mo2C catalysts

Abstract

A series of Mo 2 C catalysts have been investigated for the hydrogenation and ring opening (ROP) of naphthalene. At 573 K and 3 MPa H 2 , bulk Mo 2 C showed no selectivity for ROP whereas ROP yield on Mo 2 C/HY catalysts was dependent upon the HY zeolite SiO 2 :Al 2 O 3 ratio and the Mo 2 C loading, as shown in figure. A series of Mo 2 C catalysts have been investigated for the hydrogenation and ring opening of naphthalene. At 573 K and 3 MPa H 2 , bulk Mo 2 C showed no selectivity for ring-opening products (ROP) and, although treating the bulk catalysts in oxygen increased stability and naphthalene conversion, ROP selectivity remained low. Supporting the Mo 2 C on HY zeolites significantly increased the hydrogenation of naphthalene and the subsequent formation of ROP, as compared to the HY zeolites alone or the bulk materials. ROP yields were dependent upon the HY zeolite SiO 2 :Al 2 O 3 ratio and the Mo 2 C loading, the optimum loading being dependent upon the zeolite acidity. The maximum ROP yield of 33 wt.% was obtained with 7.4 wt.% Mo 2 C supported on HY zeolite of moderate acidity (SiO 2 :Al 2 O 3 ratio of 12) and the yield is comparable to yields reported for noble metal catalysts on acidic supports. The Mo 2 C/HY zeolite bifunctional catalysts are most effective for ring opening of naphthalene when the acidity is adjusted to an intermediate level that limits deactivation and the Mo 2 C loading provides sufficient hydrogenation capability to achieve high conversion to the primary product tetralin.