Silanized Titanium Silicate (TS-1) Molecular Sieve for Promoting the Homogeneously Catalyzed Oxidation of Cyclohexane

Abstract

The promoting effect of titanium silicate (TS-1) molecular sieve and silanized TS-1 (TS-1-S) on the homogeneous liquid oxidation of cyclohexane catalyzed by cobalt naphthenate (Co-nap) with oxygen as oxidant was investigated. Both TS-1 zeolites were efficient promoters. The conversion of cyclohexane was 7.9% with a selectivity of 83.7% when it was catalyzed by Co-nap/TS-1-S, and the reaction time was reduced to 130 min as compared to 300 min with Co-nap as the catalyst. The adsorption of Co-nap on TS-1-S, which transformed a homogeneous reaction into a “quasi-heterogeneous” reaction, was the reason for the better catalytic performance. 摘要：考察了钛硅分子筛 (TS-1) 以及硅烷化钛硅分子筛 (TS-1-S) 上环烷酸钴 (Co-nap) 催化环己烷氧化反应性能. 结果表明, TS-1 和 TS-1-S 对该反应均具有显著的促进作用, 环己烷转化率由无 TS-1 时的 3.6% 分别提高至 6.4% 和 7.9%, 产物选择性保持在 80% 左右, 反应时间由 300 min 可缩短为 130 min. 进一步的研究表明, 随着 TS-1 的加入, Co-nap 在其表面发生了吸附, 使得均相反应变成了“类多相催化反应”, 这是反应性能显著提高的主要原因. Titanium silicate (TS-1) molecular sieve was used to promote the oxidation of cyclohexane catalyzed by cobalt naphthenate. The adsorption of cobalt naphthenate on TS-1-S was the reason for the better activity.