Production of NMSBA from NMST Catalyzed by Co/Mn/Br and HPW@C Modified with ZnCl2 Solution

Abstract

Abstract2-nitro-4-methylsulfonylbenzoic acid (NMSBA) can be produced by oxidizing 2-nitro-4-methylsulfonyltoluene (NMST) with air catalyzed by Co/Mn/Br and phosphotungstic acid(HPW) loaded on activated carbon. This paper reports that the catalytic ability of the HPW@C catalyst in the oxidation of NMST to NMSBA can be improved by treating the activated carbon with ZnCl2solution. The best modification condition with ZnCl2solution is impregnating the carbon sample in 0.1 mol/L solution for 6 h followed by calcination at 600 °C for 4 h. The increase of the surface area and the acidic groups on the carbon surface enhances the catalytic ability of the HPW@C catalyst. The mesopores play an important role in the catalytic oxidation of NMST to NMSBA.

Production of NMSBA from the oxidation of NMST in the homogeneous Co/Mn/Br/H3PMoxW12−xO40 catalytic system

“…It can be seen from Table 2 that the ratio of molybdenum to tungsten in the H 3 PMo x W 12Àx O 40 synthesized by ether extraction method is very close to the theoretical value, and the deviation is very small. The ICP characterization data show that the mass fractions of molybdenum and tungsten atoms in the samples conform to the [XM 12 O 40 ] nÀ . Therefore, it can be concluded that the prepared phosphomolybdenum tungsten heteropoly acids have Keggin type structure.…”

“…He et al [ 11 ] decreased the usage of H 3 PW 12 O 40 , accelerated NMST oxidation, and increased NMSBA yield with a heterogeneous catalytic system by immobilizing H 3 PW 12 O 40 on activated carbon. Wen et al [ 12 ] improved the catalytic capability of H 3 PW 12 O 4 @C by modifying the carbon with a ZnCl 2 solution. Liu et al [ 13 ] improved the catalytic activity of H 3 PMo 12 O 40 @C by introducing H 2 SO 4 , HCl, HNO 3 , CH 3 COOH, and H 2 C 2 O 4 into the solution as competitive adsorbates for H 3 PMo 12 O 40 in the preparation of H 3 PMo 12 O 40 @C.…”

“…He et al [11] decreased the usage of H 3 PW 12 O 40 , accelerated NMST oxidation, and increased NMSBA yield with a heterogeneous catalytic system by immobilizing H 3 PW 12 O 40 on activated carbon. Wen et al [12] improved the catalytic capability of H 3 PW 12 O 4 @C by modifying the carbon with a ZnCl 2 solution. Liu et al [13] improved the catalytic activity of The catalytic capability of heteropoly acid can be adjusted by altering its central heteroatom, frameworkpolyatoms, and charge-compensating countercation due to its acidity and redox properties being changed by the displacement of those atoms.…”

Production of NMSBA catalyzed by Co/Mn/Br together with the porous carbon made from coconut shell with ZnCl2 as activator

“…Liu et al 10 used H 2 SO 4 , HCl, HNO 3 , CH 3 COOH, and H 2 C 2 O 4 as competitive adsorbates in the preparation of H 3 PMo 12 O 40 @CAC to improve the catalytic ability of H 3 PW 12 O 4 @-CAC in the production of NMSBA. Wen et al 11 upgraded the NMSBA yield in the oxidation of NMST under the catalysis of H 3 PW 12 O 4 @CAC by treating the carbon with ZnCl 2 solution.…”