Introducing tin to develop ternary metal oxides with excellent hydrothermal stability for NH3 selective catalytic reduction of NOx

Abstract

Thermal stability is crucial for the practical application of heterogeneous catalysts. In particular, the development of catalysts with excellent hydrothermal stability remains a big challenge for diesel exhaust after-treatment technologies. Here, we synthesized a Ce1W0.24Sn2Ox catalyst with high hydrothermal stability for the NOx removal from diesel engines. The catalyst shows >90 % NOx conversion at 300−550 °C even after an extreme aging treatment at 1000 °C, with much better hydrothermal stability than the Ce1W0.24Ox catalyst and the commercial catalysts such as Cu-SSZ-13 and V2O5-WO3/TiO2. The experimental and theoretical results reveal that the SnO2-related particles modified by W and Ce species show outstanding sintering resistance at high temperature, which provides sufficient Ce-W active phase for the catalytic reaction. This study may provide new opportunities for the application of metal oxide catalysts for diesel engine NOx emission control and a new idea for the development of catalysts with high thermal stability.