Effect of particle size on coal char----NO reaction

Abstract

Surface nitrogen complex formation upon reaction of coal char with NO at 600°C was studied by X-ray photoelectron spectroscopy. Particle size had a noticeable effect on the magnitude of changes, which was observed on the surface of the coal char in the nitrogen functional group. The surface increased its -NO, pyridine-N-oxide, and -NO₂ functional group contents with a decrease in particle size. The chemisorption processes of NO molecules on the char were simulated using the ab initio Hartree–Fock method and density functional theory. Molecular modeling was applied to determine the thermodynamics of the reactions. Mechanisms were proposed to explain the formation of the -NO, pyridine-N-oxide, and -NO₂ functional groups at 600°C.

Key words： NO reduction; chemisorption; particle size; X-ray photoelectron spectroscopy; density functional theory (DFT)

Acknowledgment

This work was supported by the National Natural Science Foundation of China (Grant No. 50876060).

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