磷钨酸铵盐的合成及其催化性能

Synthesis and Catalytic Properties of Ammonium-substituted Dodecatungstophopsphate

以钨酸钠为原料,采用一种新的方法合成磷钨酸,合成的酸滴加一定比例的NH4HCO3合成磷钨酸铵盐,并用之作催化剂,催化反应乙酸和正丁醇合成乙酸正丁酯.研究结果表明,制备磷钨酸的过程中,当H+∶WO42-=3∶2时生成的活性钨酸沉淀最多.酯化反应中,当醇酸物质的量之比为1∶2,催化剂用量为1.0 g,反应时间为1.5 h,反应温度在100℃时,酯化率可达最大值95.4%.

Sodium tungstate as materials, 12-tungstophosphoric acid is synthesized by a new method. Then the prepared acid reacts with NH4HCO3, and forms ammonium-substituted dodecatungstophopsphate.The catalytic performances of prepared catalysts are evaluated by catalyzing the esterification from n-butanol and acetic acid. The experimental results show that the 12-tungstophosphoric acid precipitation is obtained more at the condition of H^＋ ： WO4^2- =3 ： 2,and the optimal esterification conditions are as follows： n-butanol / acetic acid =1 ： 2.0（mol） ; the weight of catalyst is 1.0 g; the reaction time is 1.5h and the reaction temperature is 100 ℃. The yield of n-butyl acetate can reach maximum value 95.4%.