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

Preparation and medium-low temperature denitrification performance of MnO_x/sepiolite catalysts

Yi-nuo Liu, Zhi-gang Liao, Yun-he Liu, Kui-bing Jiang, Bo Peng, Ying-cai Han, Bao-hua Yang, Bin Mao, and Li-hong Lan

Guangxi Key Laboratory of Polysaccharide Materials and Modifications, School of Chemistry and Chemical Engineering, Guangxi Minzu University, Nanning, China

E-mail: lanlihong2004@163.com

Received: 16 September 2025  Accepted: 21 November 2025

Abstract:

Natural sepiolite was subjected to acid pretreatment. Subsequently, MnO_x was loaded onto both pristine sepiolite (SEP) and acid-pretreated sepiolite (NSEP) supports via an in situ growth method, yielding the MnO_x/SEP and MnO_x/NSEP catalyst series. The medium-low temperature NH₃-SCR denitrification performance of these catalysts was systematically investigated. Characterization techniques (BET, XRD, SEM, TEM, XPS, and TG) were employed to elucidate how acid pretreatment influences on the catalyst structure-performance relationship. Results demonstrate that the MnO_x/NSEP catalyst, prepared using acid-pretreated sepiolite, exhibits enhanced denitrification catalytic performance within the 150–300 °C range. Among the acids tested, nitric acid pretreatment proved more beneficial for the denitrification than hydrochloric acid or sulfuric acid. Acid pretreatment induces fiber disaggregation in sepiolite, promoting uniform loading and dispersion of the active manganese oxide components. It also strengthens the Mn-O-Si interfacial bonding interaction, improving thermal stability. This study presents a novel support modification strategy for developing efficient medium-low temperature SCR catalysts.

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Keywords: Sepiolite; Acidification; Mn-based catalyst; Medium-low temperature catalysis; NH3-SCRdenitrification

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04546-y

Chemical Papers 80 (3) 2729–2740 (2026)