The full exposure of active ingredients plays an important role in the enhancement of catalytic performance. In this work, a series of novel catalysts, Mn−Co mixed oxide nanosheets with ultrathin… Click to show full abstract
The full exposure of active ingredients plays an important role in the enhancement of catalytic performance. In this work, a series of novel catalysts, Mn−Co mixed oxide nanosheets with ultrathin thickness (about 3.5 nm) and different Mn/Co ratios (0.52, 0.69, and 1.52) vertically anchored on a support (H2Ti3O7 nanowires), are rationally developed. This unique structure not only fully exposes the active ingredients of the Mn−Co mixed oxides, but also is very favorable for the diffusion and transfer of gas molecules through the space between these standing nanosheets. As expected, the developed catalysts (MnOx‐CoOy/H2Ti3O7, MnCoTi), especially MnCoTi‐2 with the Mn/Co molar ratio of 0.69, present excellent low‐temperature selective catalytic reduction (SCR) performance, high N2 selectivity, superior water tolerance and stability. The relative turnover frequency (TOF) value over MnCoTi‐2 at 100 °C is as high as 9.25×10−4 s−1 under the gas hourly space velocity (GHSV) of 200 000 h−1, which is rarely reported among Mn‐Ti, Mn−Co, and Mn−Co‐Ti mixed oxide catalysts. The results of in situ diffuse reflectance infrared Fourier transform spectroscopy suggest that the coordinated NH3, NH4+ ions, adsorbed NO2, and bidentate nitrate are the reactive species and the Eley–Rideal and Langmuir–Hinshelwood mechanisms can be simultaneously involved on the surface of the MnCoTi‐2 at a relatively low temperature (90 °C).
               
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