Effect of Fe-loading in iron-based catalysts for the CH4 decomposition to H2 and nanocarbons

Miao Yang; Shuo Li; Yimin Deng; Jan Baeyens; Huili Zhang

doi:10.1016/j.jenvman.2023.118999

Effect of Fe-loading in iron-based catalysts for the CH₄ decomposition to H₂ and nanocarbons

J Environ Manage. 2023 Nov 15:346:118999. doi: 10.1016/j.jenvman.2023.118999. Epub 2023 Sep 24.

Authors

Miao Yang¹, Shuo Li¹, Yimin Deng², Jan Baeyens¹, Huili Zhang³

Affiliations

¹ Beijing University of Chemical Technology, Beijing Advanced Innovation Centre for Soft Matter Science and Engineering, 100029, Beijing, China.
² Beijing Institute of Technology, School of Chemistry and Chemical Engineering, 102488, Beijing, China.
³ Beijing University of Chemical Technology, College of Life Science and Technology, 100029, Beijing, China. Electronic address: Zhhl@buct.edu.cn.

PMID: 37751646
DOI: 10.1016/j.jenvman.2023.118999

Abstract

The catalytic CH₄ decomposition (CMD) over Fe-based catalyst is an economical and environmentally friendly way to produce Co_x-free H₂ and carbon nanotubes (CNTs). The Fe-loading was varied to study its influence on the catalytic performance. The highest H₂ yield (82.25%) was obtained with a 12% Fe content where the activity of the catalyst did not decrease for 3 h on-stream. A higher Fe content causes the Fe dispersion to decrease, resulting in a reduced available surface area of active sites. Different techniques were used to characterise the fresh and spent catalysts i.e., ICP-AES, XRD, H₂-TPR, SEM, TEM, and Raman spectroscopy. Plotting kinetic results as a function of 1/T, defines two different conversion ranges, being reaction rate controlled at low temperature and diffusion rate controlled at high temperature. For the reaction rate controlled regime, the Arrhenius equation provides an activation energy of 101.26 kJ/mol (E_a) and a pre-exponential factor of 393 kmol/s (A).

Keywords: Carbon nanotubes; Catalytic methane decomposition; Fe/α-Al(2)O(3); Hydrogen.