Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (3): 512-518.doi: 10.3866/PKU.WHXB201412251

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Enhanced Effect of O/N Groups on the Hg0 Removal Efficiency over the HNO3-Modified Activated Carbon

TONG Li1,2, XU Wen-Qing1, QI Hao1,2, ZHOU Xuan1, LIU Rui-Hui1, ZHU Ting-Yu1   

  1. 1. Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P. R. China;
    2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2014-10-13 Revised:2014-12-25 Published:2015-03-06
  • Contact: ZHU Ting-Yu E-mail:tyzhu@ipe.ac.cn
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2013CB430005) and National Hi-Tech Research and Development Program of China (863) (2013AA065501, 2013AA065404).

Abstract:

HNO3-modified activated carbon (AC) was prepared to determine its mercury removal ability on a fixed-bed reactor. In this study, the HNO3-modified AC was found to be effective for mercury removal in simulated flue gas. The original sample, the HNO3-modified sample and the production sample were characterized by elemental analysis, Brunauer-Emmett-Teller (BET) specific surface area measurements, scanning electron microscopy (SEM), Raman spectra, Boehm titrations, temperature programmed desorption (TPD) technique, and X-ray photoelectron spectroscopy (XPS). The results show that HNO3 treatment increases the content of oxygen and nitrogen on the AC. Compared with the physical characteristics of HNO3-modified AC, the effects of its chemical characteristics on mercury removal are more significant. The Hg0 is mainly oxidized to HgO by the HNO3-modified AC. The oxygen functional groups, possibly carbonyls, esters or anhydrides were found to be the adsorption sites for mercury removal, and these groups were reduced to hydroxyl groups or ether groups. The N-functional groups, possibly pyrrolic tautomers, were found to be the active catalytic sites. The mechanism for Hg0 removal by HNO3-modified activated carbon is proposed based on the characterization results.

Key words: Elemental mercury, Activated carbon, HNO3, Oxygen functional group, Nitrogen functional group

MSC2000: 

  • O647