Regeneration and sulfur poisoning behavior of In/H-BEA catalyst for NOx reduction by CH4
Regeneration and sulfur poisoning behavior of In/H-BEA catalyst for NOx reduction by CH4
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DOI：
10.1016/j.apsusc.2016.12.201
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发表时间：
2017-04-15
影响因子：
6.7
通讯作者：
Liu, Hongxia
中科院分区：
文献类型：
--
作者：
Pan, Hua;Jian, Yanfei;Liu, Hongxia
研究了CH4还原NOx过程中In/H-BEA催化剂的硫中毒及再生行为。在用CH4还原NO的过程中，在450℃条件下加入200 ppm SO2和10 vol.% H2O 45 h后，In/ h - bea催化剂对二氧化硫的抗性较差。In/ h - bea的硫中毒是由于抑制了NOx在Bronsted酸位点的吸附，抑制了活性位点上反应中间体的生成，以及表面硫酸盐物质的形成。表面硫酸盐的形成降低了表面活性位点的可用性，堵塞了孔隙结构，减少了催化剂的表面积。这些化学性质和结构性质的变化导致硫酸化in /H-BEA催化剂用CH4还原NO的活性严重下降。H-2还原是一种很有前途的技术，用于再生被SO2钝化的In/H-BEA，以去除稀燃和柴油尾气中的NOx。以In2O3和In(OH)(2)（+）为中间体，H-2可以将硫酸铟还原为InO+。再生温度为400℃，再生时间为60 min，可完全恢复In/H-BEA的催化活性。(C) 2016 Elsevier B.V.版权所有
Sulfur poisoning and regeneration behavior of In/H-BEA catalyst were carried out in NOx reduction by CH4. In/H-BEA catalyst exhibited a poor resistance to sulfur dioxide after addition of 200 ppm SO2 and 10 vol.% H2O into NO reduction with CH4 at 450 degrees C for 45 h. Sulfur poisoning of In/H-BEA was attributed to the inhibition of NOx adsorption on Bronsted acid sites, suppression of reaction intermediates generation on the active sites, and the formation of surface sulfate species. The formation of surface sulfate reduced the availability of surface active sites, blocked the pore structure and decreased the surface area of catalyst. These changes in chemical and textural properties resulted in a severe loss in the activity of sulfated In/H-BEA catalyst for NO reduction with CH4. H-2 reduction is a promising technology for regeneration of In/H-BEA deactivated by SO2 for removing NOx from lean-burn and diesel exhausts. Indium sulfate could be reduced by H-2 to InO+ with In2O3 and In(OH)(2)(+) as the intermediates. The optimal parameters of H2 reduction was regeneration temperature of 400 degrees C and regeneration time of 60 min which completely recovered the catalytic activity of In/H-BEA. (C) 2016 Elsevier B.V. All rights reserved.