Synthesis of Zeolitic Ti, Zr-Substituted Vanadotungstates and Investigation of Their Catalytic Activities for Low Temperature NH3-SCR
Synthesis of Zeolitic Ti, Zr-Substituted Vanadotungstates and Investigation of Their Catalytic Activities for Low Temperature NH3-SCR
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DOI：
10.1021/acscatal.1c04086
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发表时间：
2021-11
期刊：
影响因子：
12.9
通讯作者：
Meilin Tao;S. Ishikawa;Zhenxin Zhang;T. Murayama;Yusuke Inomata;Akiho Kamiyama;Ichika Nakaima;Yuan Jing;Shinya Mine;Kosuke Shimoda;Takashi Toyao;K. Shimizu;W. Ueda
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文献类型：
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作者：
Meilin Tao;S. Ishikawa;Zhenxin Zhang;T. Murayama;Yusuke Inomata;Akiho Kamiyama;Ichika Nakaima;Yuan Jing;Shinya Mine;Kosuke Shimoda;Takashi Toyao;K. Shimizu;W. Ueda
通过[W 4 O 16]8-立方烷单元与VO 2+连接体连接形成LTA-沸石型晶体结构，构建了微孔钒钨酸盐（W 4V 3 O 19，VT-1）。我们发现，通过适当的酸处理，VT-1中连接立方烷单元的VO ~（2+）位可以部分去除，而不会破坏其晶体结构。该过程涉及[W 4 O 16]8-立方烷单元和VO 2+连接体之间的氧化还原反应，并且V在酸处理期间作为V5+被去除。TiO ~（2+）或ZrO ~（2+）可引入到VO_2 ~+空位中。Ti或Zr的引入显著改善了VT-1在氧化条件下的热稳定性。Ti或Zr的引入提高了催化剂对NH3选择性催化还原NOx（NH3-SCR）反应的催化活性。
Microporous vanadotungstate (W4V3O19, VT-1) was constructed via the connection of [W4O16]8–cubane units with VO2+linkers to form an LTA-zeolite-type crystal structure. We found that the VO2+sites connecting the cubane units of VT-1 could be partially removed by an appropriate acid treatment without destroying its crystal structure. This process involved a redox reaction between the [W4O16]8–cubane units and VO2+linkers, and V was removed as V5+during the acid treatment. TiO2+or ZrO2+could be introduced into the VO2+vacancies. The introduction of Ti or Zr substantially improved the thermal stability of VT-1 under oxidizing conditions. The catalytic activity toward the selective catalytic reduction of NOxwith NH3(NH3-SCR) was improved by the introduction of Ti or Zr.