Structure and performance of a V2O5–WO3/TiO2–SiO2 catalyst derived from blast furnace slag (BFS) for DeNOx
Structure and performance of a V2O5–WO3/TiO2–SiO2 catalyst derived from blast furnace slag (BFS) for DeNOx
复制标题
DOI：
10.1039/c7ra01252g
复制
发表时间：
2017-03
期刊：
影响因子：
3.9
通讯作者：
Tuyetsuong Tran;Jian Yu;C. Li;F. Guo;Yu-sheng Zhang;Guangwen Xu
中科院分区：
文献类型：
--
作者：
Tuyetsuong Tran;Jian Yu;C. Li;F. Guo;Yu-sheng Zhang;Guangwen Xu
含钛高炉渣是一种二氧化钛含量高(约20%)、产量大(360万吨/年)的固体废物，给中国带来了严重的环境问题。BFS作为一种低成本、高效率的脱氮催化剂，已被证实具有广阔的应用前景。在本工作中，用不同掺杂量的Al_2O_3/Fe_2O_3/SO_4~(2-)−掺杂剂制备了四个来自高炉炉渣和工业钛硅的V_2O_5-WO_3/TiO_2-SiO_2样品，揭示了渣基催化剂独特的结构对催化脱氮性能的影响。催化剂表征结果表明，沸石中的Al_2O_3/Fe_2O_3/SO_42−掺杂促进了Ti-O-Si键的形成，具有丰富的结构缺陷。这种结构可能对获得高比表面积、分散良好的VOx活性物种、足够的弱酸中心以及大量的OADs和V4+物种起到了关键作用。这些结构上的优势被表现出优异的脱氮性能的催化试验所证实。然而，过多的SO42SiO_2掺杂会导致−-SiO_2颗粒团聚，形成强酸中心和大量的OADs物种，从而对催化剂的活性、选择性和催化剂寿命产生不利影响。
The titanium-bearing blast furnace slag (BFS), a solid waste with high TiO2 content (around 20%) and huge production (3.6 million tons per year), has caused serious environmental problems in China. The reuse of BFS in making DeNOx catalysts has been confirmed to be promising because of its low cost and high effectiveness for DeNOx. In this work, four V2O5–WO3/TiO2–SiO2 samples from BFS and commercial Ti/Si were made with different amounts of Al2O3/Fe2O3/SO42− dopants to reveal the unique structure effect of a slag-based catalyst on the catalytic behavior for DeNOx. Catalyst characterization clarified that the Al2O3/Fe2O3/SO42− dopants from BFS may facilitate the formation of Ti–O–Si linkages with abundant structure defects. The structure possibly played a key role in acquiring a high surface area, well-dispersed active VOx species, sufficient weak acid sites and a high amount of Oads and V4+ species for the slag-based catalyst. These advantages in structure were confirmed by catalytic tests showing superior DeNOx performances. Nonetheless, too many SO42− dopants caused agglomeration of TiO2–SiO2 particles, formation of strong acid sites and a high amount of Oads species to negatively impact the DeNOx activity, selectivity and catalyst lifetime.