Characterization of silica-supported copper catalysts by means of temperature-programmed reduction

The effect of the preparation procedure on the reduction behavior of silica-supported copper catalysts was studied. The reduction process was monitored by measurement of the hydrogen consumption during temperature-programmed reduction (TPR). The catalysts were prepared by a variety of methods, viz. impregnation, ion-exchange, homogeneous deposition-precipitation, and co-precipitation. The results show that the reduction behavior of the catalysts strongly depends on the preparation method as well as on the thermal pretreatment. Comparison of the TPR profiles of the catalysts with results obtained on mineral copper hydrosilicates and bulk copper oxide facilitated identification of the copper precursor species present in the catalysts.