采用一系列金属氧化物对商用SCR催化剂进行掺杂改性,筛选出最优Ce掺杂SCR催化剂,模拟实际烟气组分,考察了Ce改性催化剂对烟气中Hg0氧化的影响。实验结果表明,Ce掺杂比例适当可显著提高其催化活性,Ce最佳负载量为9%时,Hg0的催化氧化效率比未掺杂SCR催化剂提高近40%,BET和XRD也显示,CeO2在催化剂表面分散程度较好,未出现聚集现象。烟气工况对Hg0的催化氧化具有重要影响,其中,烟气组分HCl显著促进了Ce改性催化剂对Hg0的氧化,在一定温度范围内,Hg0的氧化效率随着温度升高而增加,在最佳空速、温度和烟气组分浓度时,Hg0的催化氧化效率可达95.11%。此外,掺杂CeO2之后SCR催化剂的脱硝性能并未受到影响。%A series of metal oxides were employed to modify the commercial SCR catalyst, and the Ce modified SCR catalyst was selected and then subjected to detailed catalytic oxidation of Hg0 by using the simulated flue gas. The results indicated that the catalytic activity of the catalyst was increased remarkably after the Ce modification, and the highest catalytic oxidation of Hg0 was obtained from the modified SCR catalyst with 9%Ce loading, being 40% higher than that of the non-modified SCR catalyst. The BET and XRD analysis indicated that the surface area of the 1% ~9% Ce modified SCR catalyst was no significant change compared with the non-modified SCR catalyst, and the CeO2 was well dispersed on the catalyst surface, without any aggregation. The flue gas condition had great effects on the Hg0 conversion. The catalytic oxidation of Hg0 would be significantly increased by HCl, and also increased as the increasing of the temperature in a certain range. The highest catalytic oxidation efficiency reached 95. 11% at the optimal space velocity, temperature and flue gas components. In addition, the CeO2 doping did not affect the denitration efficiency of the SCR catalyst.
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