ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Promotional effect of NdO_x on MnCo₂O₄ spinel oxide for NH₃-SCR reaction: activity and mechanism study

Hong An, Dan Zhang, Yun-wei Xu, Yi-zhen Dong, Dong Ye, Fei-ni Chen, and Rui-tang Guo

State Nuclear Electric Power Planning Design & Reseach Institute Co., Ltd., Beijing, People’s Republic of China

E-mail: Richard32@126.com

Received: 18 January 2026  Accepted: 25 May 2026

Abstract:

To address the issue regarding the effective removal of NO_x under conditions with fluctuating temperatures, developing a catalyst that exhibits satisfactory selective catalytic reduction (SCR) performance in a wide temperature range is the research hotspot in environmental field. In this study, the virgin and NdO_x-doped MnCo₂O₄ spinel catalysts were prepared using the sol-gel method, aiming to investigate the effect of NdO_x on SCR performance. The optimal sample, with an Nd/Mn molar ratio of 0.1, showed > 90% NO_x conversion within a temperature range of 200–350 °C and maintained > 96% N₂ selectivity over the whole temperature range. The enhanced SCR performance of the NdO_x-doped catalysts could be attributed to several factors, including enlarged specific surface area, more developed pore structures, greater acidity and oxidizability, and improved NO oxidation capability. The Langmuir-Hinshelwood mechanism contributed to the SCR reactions for the pristine and NdO_x-doped catalysts; doping NdO_x improved the reactivity of the formed intermediates during the catalytic cycle. Finally, the NdO_x-modified catalyst exhibited better sulfur resistance; during the 10-h sulfur deactivation cycle, catalyst’s NO_x conversion remained above 86%, ~ 13% higher than that of the pristine MnCo₂O₄. Given its good SCR performance under high gas hourly space velocity conditions, it seems that the NdO_x-modified catalyst shows certain industrialization prospects.

Graphical abstract

Keywords: SCR; NdOx; MnCo2O4; Acidity and oxidizability; Mechanism

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05116-6

Chemical Papers 80 (10) 12063–12072 (2026)