Catalytic reduction of nitrate in water over Pd-Cu/TiO2 catalyst: Effect of the strong metal-support interaction (SMSI) on the catalytic activity

In this study, we prepared TiO2-supported Pd-Cu catalysts of different anatase/rutile phase compositions, which were used in a nitrate reduction in water. It was shown that the catalysts containing a greater anatase phase composition had higher catalytic performance. Through characterization studies using H-2-temperature programmed reduction (H-2-TPR) and X-ray photoelectron spectroscopy (XPS), the observed trend of the catalytic activity was correlated to the degree of the strong metal-support interaction (SMSI) over the catalysts. The SMSI occurred through pre-treatment of the catalysts by H-2 reduction (at 200 degrees C), which resulted in increased partially reduced TiO2-x, and electron-rich active metal (Pd and Cu) states at the catalyst of higher composition of anatase phase. The relationships between the changes in the properties and activities of the catalysts as a result of the anatase phase composition are discussed. (c) 2013 Elsevier B.V. All rights reserved.