A highly effective urchin-like MnCrOx catalyst for the selective catalytic reduction of NOx with NH3.

• MnCrO x -UL shows superior NH 3 -SCR performance and high resistance to SO 2. • More ad-NH 3 and ad-NO x species are available on the surface of MnCrO x -UL. • The ad-NH 3 and ad-NO x species over MnCrO x -UL are of higher reactivity. A novel urchin-like catalyst (MnCrO x -UL) was successfully synthesized by hydrothermal redox reaction. In addition, a reference sample (MnCrO x) was prepared by co-precipitation process for comparison. Experimental results revealed that MnCrO x -UL showed superior NH 3 -SCR performance in the temperature range of 150–350 °C and high resistance to SO 2. The results of characterization demonstrated that MnCrO x -UL showed larger surface area, more acidic sites, higher redox capacity and more oxygen vacancies compared with MnCrO x. Additionally, more activated adsorbed species over MnCrO x -UL sample surface could also effectively improve the NH 3 -SCR performance at low temperature. [ABSTRACT FROM AUTHOR]