Synergistic Catalytic Removal of NO x and n -Butylamine via Spatially Separated Cooperative Sites.

Synergistic control of nitrogen oxides (NO x ) and nitrogen-containing volatile organic compounds (NVOCs) from industrial furnaces is necessary. Generally, the elimination of n -butylamine ( n -B), a typical pollutant of NVOCs, requires a catalyst with sufficient redox ability. This process induces the production of nitrogen-containing byproducts (NO, NO 2 , N 2 O), leading to lower N 2 selectivity of NH 3 selective catalytic reduction of NO x (NH 3 -SCR). Here, synergistic catalytic removal of NO x and n -B via spatially separated cooperative sites was originally demonstrated. Specifically, titania nanotubes supported CuO x -CeO 2 (CuCe-TiO 2 NTs) catalysts with spatially separated cooperative sites were creatively developed, which showed a broader active temperature window from 180 to 340 °C, with over 90% NO x conversion, 85% n -B conversion, and 90% N 2 selectivity. A synergistic effect of the Cu and Ce sites was found. The catalytic oxidation of n -B mainly occurred at the Cu sites inside the tube, which ensured the regular occurrence of the NH 3 -SCR reaction on the outer Ce sites under the matching temperature window. In addition, the n -B oxidation would produce abundant intermediate NH 2 *, which could act as an extra reductant to promote NH 3 -SCR. Meanwhile, NH 3 -SCR could simultaneously remove the possible NO x byproducts of n -B decomposition. This novel strategy of constructing cooperative sites provides a distinct pathway for promoting the synergistic removal of n -B and NO x .