Synthesis and Catalytic Performance of Cotton-Derived Mn–Ce and Mn–Co–Ce Biomorphic Fibers for Soot Combustion and CO Oxidation

Abstract

Biomorphic mineralization was employed to synthesize novel Mn–Ce and Mn–Co–Ceoxide fibers using commercial cotton as a biotemplate, aiming to assess their catalyticperformance in diesel soot combustion and CO oxidation. Two synthesis protocols—onewith and one without citric acid—were investigated. The inclusion of citric acid led tofibers with more uniform morphology, attributed to improved precursor distribution,although synthesis yields decreased for Co-containing systems. In soot combustion tests,Mn–Ce catalysts synthesized with citric acid outperformed their monometallic counterparts.While cobalt incorporation enhanced the mechanical robustness of the fibers, it did notsignificantly boost catalytic activity. Selected formulations were also evaluated for COoxidation, with Mn–Co–Ce fibers achieving T50 values in the 240–290 ◦C range, comparable to Co–Ce nanofibers reported in the literature. These results demonstrate that biomorphic fibers produced through a simple and sustainable route can offer competitive performance in soot and CO oxidation applications.