Substitution of WO3 in V2O5/WO3–TiO2 by Fe2O3 for selective catalytic reduction of NO with NH3
Substitution of WO3 in V2O5/WO3–TiO2 by Fe2O3 for selective catalytic reduction of NO with NH3
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DOI：
10.1039/c2cy20383a
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发表时间：
2012-12
影响因子：
5
通讯作者：
Shijian Yang;Chizhong Wang;Lei Ma;Yue Peng;Zan Qu;N. Yan;Jinghuan Chen;Huazhen Chang;Junhua Li
中科院分区：
文献类型：
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作者：
Shijian Yang;Chizhong Wang;Lei Ma;Yue Peng;Zan Qu;N. Yan;Jinghuan Chen;Huazhen Chang;Junhua Li
为了提高N2选择性和降低成本，用低成本的Fe2O3代替V2O5/WO3 - tio2中的WO3，用NH3选择性催化还原NO。V2O5/ Fe2O3-TiO2上的SCR反应主要遵循Eley-Rideal机制（即活性氨种与气态NO之间的反应）。在V2O5/ WO3-TiO2上有两种活性组分（即V5+和Fe3+）对吸附的NH3进行活化。V2O5/ Fe2O3-TiO2上的酸位主要来源于载体Fe2O3-TiO2，因此吸附的NH3更倾向于被Fe3+而不是V5+活化。由于V5+与Fe2+在V2O5/ Fe2O3-TiO2表面的快速电子转移，使得V5+能加速Fe3+在Fe2O3-TiO2表面的再生，从而促进了Fe3+对吸附NH3的活化。由于吸附在V2O5/ Fe2O3-TiO2上的部分NH3没有被Fe3+活化，因此失活的NH3可以被表面的V5+活化。结果表明，2%的V2O5/ Fe2O3-TiO2在300-450℃下表现出优异的SCR活性、N2选择性和H2O/SO2耐久性。此外，由于V2O5/ Fe2O3-TiO2的固有磁化特性，外加磁场可以阻止其向粉煤灰中发射2%的V2O5/ Fe2O3-TiO2。因此，2% V2O5/ Fe2O3-TiO2是一种很有前途的低成本NO排放控制催化剂。
To improve N2 selectivity and lower the cost, WO3 in V2O5/WO3–TiO2 was substituted by a low cost composition Fe2O3 for selective catalytic reduction (SCR) of NO with NH3. The SCR reaction over V2O5/Fe2O3–TiO2 mainly followed the Eley–Rideal mechanism (i.e. the reaction between activated ammonia species and gaseous NO). There were two active components on V2O5/WO3–TiO2 for the activation of adsorbed NH3 (i.e. V5+ and Fe3+). The acid sites on V2O5/Fe2O3–TiO2 mainly resulted from the support Fe2O3–TiO2, so the adsorbed NH3 preferred to be activated by Fe3+ rather than by V5+. V5+ on V2O5/Fe2O3–TiO2 could accelerate the regeneration of Fe3+ on Fe2O3–TiO2 due to the rapid electron transfer between V5+ and Fe2+ on the surface, so the activation of adsorbed NH3 by Fe3+ was promoted. As some NH3 adsorbed on V2O5/Fe2O3–TiO2 was not activated by Fe3+, the inactivated NH3 could then be activated by V5+ on the surface. As a result, 2% V2O5/Fe2O3–TiO2 showed excellent SCR activity, N2 selectivity and H2O/SO2 durability at 300–450 °C. Furthermore, the emission of 2% V2O5/Fe2O3–TiO2 to the fly ash can be prevented by an external magnetic field due to its inherent magnetization. Therefore, 2% V2O5/Fe2O3–TiO2 could be a promising low-cost catalyst in NO emission control.