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A "pseudo photocatalysis" process, being initiated between plasma and N-type semiconductors in the absence of light, was investigated for NO removal for the first time via dynamic probing of reaction processes by FT-IR spectra. It was demonstrated that N-type semiconductor catalysts could be activated to produce electron-hole (e-h) pairs by the collision of high-energy electrons (e*) from plasma. Due to the synergy of plasma and N-type semiconductors, major changes were noted in the conversion pathways and products. NO can be directly converted to NO and NO instead of toxic NO, owing to the formation of O and ·OH present in catalysts. New species like O or ·O may be generated from the interaction between catalyst-induced species and radicals in plasma at a higher SIE, leading to deep oxidation of existing NO to NO. Experiments with added trapping agents confirmed the contribution of e and h from catalysts. A series of possible reactions were proposed to describe reaction pathways and the mechanism of this synergistic effect. We established a novel system and realized an e*-activated "pseudo photocatalysis" behavior, facilitating the deep degradation of NO. We expect that this new strategy would provide a new idea for in-depth analysis of plasma-activated catalysis phenomenon.

In this study, CePO 4 catalyst (referred as Ce-P-O) was for the first time employed to capture elemental mercury (Hg 0 ) under a simulated coal-fired flue gas condition. As compared with commercial SCR catalyst (i.e. V-W-Ti), the Ce-P-O catalyst had showed a much better performance in Hg 0 removal. The high Hg 0 adsorption capacity, abundant active oxygen species and excellent SO 2 poisoning resistance were account for such performance for Ce-P-O catalyst. After subjected to individual flue gas component conditions, it was found that the presence of NO can significantly improve the Hg 0 removal efficiency over the Ce-P-O catalyst whilst the HCl however did not show promotion effect as expected. The former was proposed due to the generated NO 2 (originated from NO oxidation) could react with Hg 0 ad-species (e.g. Hg 2 O), regenerating the HgO and hence enhancing the Hg 0 chemisorption. The latter was found owning to the absence of Deacon reaction over the catalyst.

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