Application of XPS method in the research into Ni ion-modified montmorillonite as a SO2 sorbent

A series of montmorillonites with adsorbed nickel ions was prepared through adsorption of nitrates from water solutions; there were four methods adopted. The surface of the sample under modification was investigated with the method of argon adsorption and XPS (X-ray photoelectron spectroscopy). SO2 was investigated on nickel-modified montmorillonites. Nickel cations were adsorbed on the montmorillonite surface as Ni2 + in Ni(OH)2 or NiO. Montmorillonite — after nickel adsorption — adsorbs SO2 physically. An addition of Mont–Ni to hard coal in a ratio 1:500 reduces SO2 emissions in the combustion process by 75–85%. Waste bentonite can be utilized for reducing SO2 emissions after processing.

► Ni cations were adsorbed on the montmorillonite surface as Ni2 + in Ni(OH)2 or NiO.
► Montmorillonite — after nickel adsorption — adsorbs SO2 physically.
► Mont–Ni add to hard coal (1:500) decreased SO2 emissions in the combustion by 75–85%.
► Waste bentonite can be utilized for reducing SO2 emissions after processing.