A superior Fe-Zr mixed oxide catalyst for the simultaneous reduction of NO and SO2 with CO

Abstract

A series of Fe-Zr mixed-metal oxides were prepared and examined for the simultaneous reduction of NO and SO2 with CO. The catalyst containing 40 mol% exhibited near-complete conversion of both pollutants at a minimum temperature of 350 °C and a GHSV of 90,000 h−1. The addition of Fe3+ to ZrO2 decreased the crystallinity of the latter phase and significantly enhanced surface area. Concentrations of 30 mol% or greater produced segregated FeOx phases, which affected catalytic performance in distinctly different ways: supported Fe3+ (30 mol%) possessed similar activity to doped Fe3+; α-Fe2O3 (50 mol%) inhibited activity due to its’ lower reducibility; an amorphous phase (40 mol%) promoted iron-weighted areal activity. A complete identification of the ambiguous component was not successfully established, but the obtained properties revealed that it exhibited weaker interaction with the support and had a size greater than that of oligomeric-Fe2O3 yet smaller than 3 nm.