M-Cresol Chemisorption on a Porous Iron-Containing Sorbent Prepared from the Carbon Residue after Lignin Processing: I. Pore Structure and Adsorption Ability of the Sorbent

Abstract

The pore structure of the new adsorbent prepared from carbon-containing residues after catalytic carbon dioxide reforming of lignin of wood origin and the features of m-cresol chemisorption on this adsorbent were studied. The main step of the pore structure formation is treatment of the iron-containing carbon residue with carbon dioxide in a plasma catalytic mode, stimulated by microwave radiation. Iron-containing clusters were formed on the surface of the initial lignin and were used as a catalyst in the first step of its processing. The sorbent has a developed porous structure. The total pore volume is 0.65 cm3/g, with the micropore volume of 0.18 cm3/g and mesopore volume of 0.42 cm3/g. The adsorbent is characterized by unimodal distribution of adsorption pores with respect to effective radii with the diameter of 3.8 nm. The m-cresol adsorption dynamics was studied in situ by IR spectroscopy. The adsorption involves chemical transformation of cresol with the formation of Ph–O–C bonds between the phenyl ring of cresol and terminal (carbon or oxygen) atoms of the adsorbent.