Recent developments of core–shell structured catalysts for the selective catalytic reduction of NOx with ammonia

Abstract

Selective catalytic reduction of NO_x with ammonia (NH₃-SCR) is an efficient and established technology for removing NO_x emission from anthropogenic sources. The commercial de-NO_x catalysts based on V₂O₅–WO₃/TiO₂ possess some significant drawbacks limiting their applicability, including narrow operating temperature window, biotoxicity, poor hydrothermal stability and SO₂/H₂O intolerance. To circumvent these shortcomings, modifications of existing V₂O₅–WO₃/TiO₂ catalysts as well as development of novel catalysts have been investigated intensively. Recently, the unique properties of core–shell structures and their extensive application within, e.g. biotechnology, pharmaceutics, electrochemical cells, optics as well as catalysis have also made their use in NH₃-SCR attractive. This review summarizes recent material developments and provides an up-to-date appraisal of core–shell structured catalyst design and assembly for NH₃-SCR, including classification, synthesis, catalytic performance as well as structure–property relationships. The review may inspire future developments within the NH₃-SCR technology leading to novel catalyst designs with improved de-NO_x performance.