Tungstophosphoric acid supported on titania: A solid acid catalyst in benzylation of phenol with benzylalcohol
Tungstophosphoric acid supported on titania: A solid acid catalyst in benzylation of phenol with benzylalcohol
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DOI：
10.1016/j.catcom.2006.08.027
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发表时间：
2007-05
影响因子：
3.7
通讯作者：
S. M. Kumbar;S. B. Halligudi
中科院分区：
文献类型：
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作者：
S. M. Kumbar;S. B. Halligudi
以二氧化钛负载磷钨杂多酸（TPA）为催化剂，苯酚和苯甲醇液相苄基化反应。采用湿法浸渍法制备了不同TPA负载量（10-25%）的催化剂，并在700°C下焙烧，采用XRD、比表面积、FTIR等手段对催化剂进行了表征，采用NH3-TPD程序升温脱附、FTIR吡啶吸附等手段对催化剂的酸性进行了测定。该催化剂由通式xPTiO 2 −y表示（其中x=wt%，P=TPA，y=煅烧温度，以°C计）。20 PTiO 2 -700催化剂在不同温度下焙烧，考察了焙烧温度对催化剂活性的影响。20 PTiO 2 -700催化剂的酸性最强，对苯酚和苯甲醇的苄基化反应活性最高。考察了反应温度、催化剂用量、反应物摩尔比对苯酚转化率和产物选择性的影响。在130°C、苯酚与苯甲醇的摩尔比为2、反应时间为1h的条件下，苯甲醇（BA）的转化率为98%，苯甲基苯酚（BP）、苯甲基醚（PBE）和苯甲基醚（BE）的选择性分别为83.6%、9.4%和7%。
Benzylation of phenol with benzylalcohol was carried out in liquid phase over tungstophosphoric acid (TPA) supported on titania. The catalysts were prepared with different TPA (10–25%) loading by wet impregnation method, were calcined at 700°C and characterized by XRD, surface area, FTIR and acidity of the catalysts was measured by temperature programmed desorption of NH3–TPD, FTIR pyridine adsorption. The catalysts have been represented by a general formula as xPTiO2−y (where x=wt%, P=TPA, and y=calcination temperature in °C). The 20PTiO2catalyst calcined at various temperatures to know the effect of calcination temperature on activity of the catalyst and the 20PTiO2-700 showed highest activity in benzylation of phenol with benzylalcohol because it had highest acidity. The effects of temperature, catalyst weight, mole ratio of the reactants on conversion of phenol and product selectivities have been optimized. 20PTiO2-700 catalyst gave conversion of benzylalcohol (BA) 98% and the selectivity to benzyl phenol (BP) 83.6%, phenyl benzyl ether (PBE) 9.4%, benzylether (BE) 7% at 130°C, phenol to benzylalcohol molar ratio 2 and in 1h.