Co-Mn-Br液相催化氧化β-甲基萘制β-萘甲酸

LIQUID PHASE CATALYTIC OXIDATION OF β-METHYLNAPHTHALENE TO β-NAPHTHOIC ACID OVER Co-Mn-Br CATALYST

在高压反应釜中考察了操作方式、催化剂配比及用量、溶剂用量、反应压力、反应温度及添加水对Co-Mn-Br液相催化氧化β-甲基萘制β-萘甲酸反应的影响。结果表明,恒压操作方式优于分步恒压操作方式。甲基萘催化氧化体系存在明显的诱导期,时间长短与催化剂组成和反应条件有关。催化剂中Co、Br的量多时氧化反应快,但Br的量增多导致产物颜色加深。水对氧化反应有抑制作用,添加水量达到7%时严重阻止了氧化反应的进行。采用Co-Mn-Br原子比为1∶1∶2的催化剂和恒压操作方式,较适宜的工艺反应参数为催化剂用量1%,120℃,0.6MPa。在此条件下,β-萘甲酸收率达93.7%。

The Effects of operation mode, catalyst composition and loading, amount of solvent, reaction pressure and temperature as well as water addition on the liquid phase catalytic oxidation of β- methylnaphthalene to β-naphthoic acid over Co-Mn-Br catalyst have been investigated in a high-pressure reactor. The results showed that the pressure-constant operation mode was better than the step-wise pressure rise operation mode. It has been demonstrated that oxidation occurred with an induction period, and the time length was determined by both the catalyst composition and oxidation conditions. More Co or Br in the catalyst speeded up the oxidation, while more Br resulted in the formation of deep colored products. Water had a negative effect on the oxidation, and the reaction did not happen with 7; water addition. Using a Co-Mn-Br catalyst of 1 ： 1 ： 2 atomic ratio with the pressure-constant operation mode, the appropriate reaction parameters were. 1% catalyst loading, 120 ℃ and 0.6 MPa. Under these conditions, a β-naphthoic acid yield of about 93.7% was realized.