IR CHARACTERIZATION OF SULFATED ZIRCONIA DERIVED FROM ZIRCONIUM SULFATE

Surface characterization of a sulfate-derived zirconia sample containi ng approximately 1 wt% S was performed by IR spectroscopy. Several typ es of sulfate groups were detected which are resistant to heating in v acuo up to 973 K. By using CO as a spectroscopic probe, two kinds of L ewis acid sites were identified which were assigned to surface Zr4+ io ns in different environments. Comparison with corresponding data for a nearly sulfate-free zirconia sample showed that sulfated zirconia has an enhanced Lewis acidity.