Selective catalytic reduction of NOx with ammonia over ceria-tungstate catalysts

Abstract

NO_x, a prominent class of air pollutants, contributes significantly to environmental problems such as photochemical smog and acid rain, posing severe risks to both ecosystem integrity and public health. Among the available mitigation strategies, ​​selective catalytic reduction (SCR) using NH₃ as a reductant​​ has emerged as the most effective and well-established technology for NO_x abatement in stationary and mobile emission sources. Within the spectrum of SCR catalysts, ​​ceria-tungstate composites​​ have garnered considerable attention due to their ​​broad operational temperature window, facile synthesis, and eco-friendly characteristics​​. This review systematically examines recent advances in ​​NO_x elimination via ceria-tungstate-based SCR catalysts​​, with a focus on ​​three critical performance metrics​​, namely catalytic activity, N₂ selectivity, and poisoning resistance. We highlight state-of-the-art strategies for enhancing these properties, supported by a mechanistic analysis that provides ​​atomic-level insights​​ into the underlying reaction pathways. Furthermore, we discuss the interplay between ​​catalyst physicochemical properties and SCR efficiency​​, offering a holistic perspective on structure–activity relationships. Finally, we outline future research directions, emphasizing the need for multiscale optimization​​ of ceria-tungstate catalysts—spanning nanostructural engineering, mass-transfer enhancement, and techno-economic feasibility—to bridge the gap between laboratory-scale innovation and industrial deployment.