Preparation, characterisation of molybdophosphoric and tungstophosphoric acid intercalated zinc aluminium hydrotalcite-like compounds and their catalytic evaluation towards the oxidative bromination of phenol
Preparation, characterisation of molybdophosphoric and tungstophosphoric acid intercalated zinc aluminium hydrotalcite-like compounds and their catalytic evaluation towards the oxidative bromination of phenol
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DOI：
10.1016/j.catcom.2006.03.012
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发表时间：
2006-11
影响因子：
3.7
通讯作者：
K. Parida;S. Parija;J. Das;P. Mukherjee
中科院分区：
文献类型：
--
作者：
K. Parida;S. Parija;J. Das;P. Mukherjee
采用磷钨酸（TPA）和磷钨酸（MPA）插层的锌铝类水滑石（ZAH）作为催化剂，对苯酚的溴氧化反应进行了研究。采用共沉淀法制备ZAH。以对苯二甲酸插层ZAH为前驱体，采用间接法对MPA和TPA进行插层。采用XRD、FT-IR、BET比表面积、表面酸性等手段对材料进行了表征。以KBr为溴源，H2 O2为氧化剂，研究了它们对苯酚氧溴化反应的催化活性。发现在负载15wt%磷钨酸的样品的情况下，转化率最大;苯酚转化率为82%，对位选择性为58%，邻位选择性为38%，二溴选择性为4%。
Oxybromination of phenol was carried out using an efficient and highly regioselective catalyst that is molybdophosphoric acid (MPA) and tungstophosphoric acid (TPA) intercalated zinc aluminium hydrotalcite-like-compounds (ZAH). The ZAH was prepared by co-precipitation method. The intercalation of MPA and TPA was done following indirect method by taking terephthalic acid intercalated ZAH as the precursor. All the materials were characterized by XRD, FT-IR, BET-surface area and surface acidity. The catalytic activity of these materials towards oxybromination of phenol was studied using KBr as a bromine source and H2O2as an oxidant. The percentage of conversion was found to be maximum in case of 15wt% molybdophosphoric acid loaded sample; 82% of phenol conversion with 58% para, 38% ortho and 4% dibromo selectivity.