Li Sha, Yu Ruopeng, Xu Bonan, Wang Zhikun, Wu Chunzheng, Guo Jianzhong
Key Laboratory of Chemical Utilization of Forestry Biomass in Zhejiang Province, College of Chemistry and Materials Engineering, Zhejiang A & F University Hangzhou 311300 China
RSC Adv. 2022 May 4;12(21):13406-13411. doi: 10.1039/d2ra00519k. eCollection 2022 Apr 28.
ZrO-WO mixed oxide plays an essential role in the chemical and petroleum industries. So far, very little work has paid attention to the activation of the low activity of ZrO-WO catalysts. In this work, poorly reactive ZrO-WO was prepared as a model catalyst by a sol-gel method and it was accompanied by post-hydrothermal treatment with various solutions. The catalytic results in the Friedel-Crafts reaction of anisole and benzyl alcohol showed that the post-hydrothermal treatment with ethylenediamine or ammonium hydroxide solutions dramatically improved the activity of ZrO-WO, while the hydrothermal treatments with water or ammonia chloride solution resulted in poorer activity and selectivity. The former treatments were found to induce a huge transformation of the ZrO crystal from monoclinic to tetragonal as well as a significant increase in acidic WO clusters that anchored onto ZrO. The generation of the WO clusters was responsible for the activation of ZrO-WO.
ZrO-WO混合氧化物在化学工业和石油工业中起着至关重要的作用。到目前为止，很少有工作关注ZrO-WO催化剂低活性的活化。在这项工作中，通过溶胶-凝胶法制备了反应活性较差的ZrO-WO作为模型催化剂，并对其进行了各种溶液的水热后处理。苯甲醚与苯甲醇的傅克反应的催化结果表明，用乙二胺或氢氧化铵溶液进行水热后处理可显著提高ZrO-WO的活性，而用水或氯化铵溶液进行水热处理则导致活性和选择性较差。发现前一种处理可诱导ZrO晶体从单斜晶向四方晶发生巨大转变，以及锚定在ZrO上的酸性WO簇显著增加。WO簇的产生是ZrO-WO活化的原因。
