Catalytic Reduction of Nitrate on Pd-In/Al2O3 Catalysts in Aqueous Solution. Comparison of Continuous and Batch Reactors.

MENDOW, GUSTAVO; MARCHESINI, F. ALBANA; MIRO, EDUARDO E.; QUERINI, CARLOS A

Salamanca, España

Congreso; EuropaCat IX: Catalysis for a Sustainable World; 2009

The pollution of natural waters, either in river flows, lakes or wells with nitrates is one of the most serious problems that have emerged in recent years in the field of water pollution. For this reason, a very promising alternative is catalytic removal of these species through bimetallic catalysts. In this paper we study the correlation between experimental reactions in batch and continuous fixed bed reactor. The deactivation of the catalyst is assessed, in reaction and by characterization techniques as XRD and TPR. In addition we present the alternative to acidify the solution by feeding CO2 so as to eliminate the pH gradients in the catalyst bed. It was found that the Pd 1%-In 0.25%/Al2O3 catalyst shows deactivation possibly due to the formation of new species such as indium oxides or alloys. It was further noted that the feed saturation with CO2 improved selectivity and conversion with respect to HCl.