On the Nature and Location of Organic Template Molecules and Their Effect on the Stability and Redox Properties of Microporous CoAlPO-34 Catalyst

Abstract

Small-pore CoAlPO-34 materials were synthesized with a variety of organic template molecules and were characterized in detail, employing microcrystal diffraction, powder diffraction and in situ combined XRD/XAS techniques. We found that, when two template molecules or two nitrogen atoms of a single template molecule are present inside the chabazitic cage, the concentration of cobalt present in the system is ca. 25 at%, which introduces instability in the framework structure during the removal of the organic template. In contrast, when only one template molecule is present, it is possible to control the concentration of Co(II) ions in the framework to ca. 10 at%; these systems show good structural integrity and redox chemistry that was exploited for the regio-selective conversion of linear alkane molecules.