The influence of the zeolitic support on the reducibility of incorporated NI 2+ cations

Abstract

On a series of NiY stabilized zeolite samples, differing in method of Ni 2+ ions incorporation, Si/Al ratio and acidity of OH groups, the influence of the zeolitic matrix on the reducibility of Ni 2+ ions was studied using temperature programmed reduction (TPR), i.r. and adsorption. The stabilized structure enables the reduction of Ni 2+ ions even at an ion exchange degree of 6 Ni 2+ per unit cell. The Ni 2+ ions incorporated by impregnation of the zeolite with Ni-ammocomplex exhibit higher reducibility than those incorporated by ion exchange. On the partially dealuminated samples, the reducibility of Ni 2+ is proportional to the Si/Al ratio. The reducibility of Ni 2+ ions is suppressed by the presence of acidic structural OH groups in zeolite.