Two Reaction Pathways in the Selective Catalytic Reduction of NO x by C6H14 Over Ag–Al2O3 with H2 Co-Feeding

摘要

The NO x reduction with n-C6H14 was studied over a 3% Ag/Al2O3 catalyst in the presence of hydrogen. The catalyst performance was evaluated by varying the H2 concentration from 0 to 1600 ppm and by comparing the results with blank runs in which an empty reactor with no catalyst was used. Two distinct reaction pathways were revealed: one at low-temperature (Treact < 370 °C) and another one at high-temperature (Treact > 370–390 °C). Co-feeding of H2 promotes the reaction within the 150–360 °C interval. The high-temperature pathway (Treact > 370–390 °C) seems to be almost independent of hydrogen co-feeding. The homogeneous gas-phase NO x oxidation initiated by NO presumably plays an important role in this high-temperature pathway.