Synthesis and Catalytic Activity of Activated Carbon Supported Sulfonated Cobalt Phthalocyanine in the Preparation of Dimethyl Disulfide

Zhiliang Cheng,Mingxing Dai,Daomin Zheng,Shuo Li,Rujie Yao,Xuejun Quan,Yaling Liu

doi:10.3390/app9010124

Zhiliang Cheng, Mingxing Dai + Show 5 more

Open Access

https://doi.org/10.3390/app9010124

Copy DOI

Journal: Applied sciences	Publication Date: Dec 31, 2018
Citations: 9	License type: CC BY 4.0

Affiliation: Chongqing University of Technology

Abstract

The Merox process was widely applied in the fine chemical industry to convert mercaptans into disulfides by oxidation with oxygen, including dimethyl disulfide (DMDS). In this paper, a new activated carbon (AC)-supported sulfonated cobalt phthalocyanine (AC-CoPcS) catalyst was prepared through the chemical linkage of ethylenediamine between them. UV−VIS, FT-IR, BET, and XPS were used to characterize the structure of the new catalyst. Then AC-CoPcS was applied to catalyze sodium methylmercaptide (SMM) oxidation for the preparation of DMDS. The effect of process parameters, such as reaction time, catalyst dosage, reaction temperature, and oxygen pressure on SMM conversion per pass (CPPSMM), yield (YieldDMDS), and purity of the DMDS (PurityDMDS) product were investigated to evaluate the catalytic performance of AC-CoPcS. The new supported catalyst exhibits better catalytic performance than the commercial one and can be properly reused four times to obtain CPPSMM and YieldDMDS higher than 90% and 70%. Under the optimum experimental conditions, the CPPSMM and YieldDMDS could reach as high as 98.7% and 86.8%, respectively, and the purity of the DMDS product is as high as 99.8%. This new supported catalyst exhibits good industrial application prospects.

Highlights

As an important fine chemical product, dimethyl disulfide (DMDS) is widely used as a soil fumigant [1,2,3], herbicide [4], food additive [5], sulfide hydrogenation catalyst, and chemical raw material [6]
90.5% to 98.7% when the P(O2 ) increases from 0.5 MPa to 0.9 MPa, and decreases slightly to 96.8% when P(O2 ) continues to increase to 1.0 MPa. These results indicate the fact that sodium methylmercaptide (SMM) is much easier to react with oxygen, but the reaction condition is much harsher to obtain a high yield of the DMDS product
A new activated carbon (AC)-supported sulfonated cobalt phthalocyanine (AC-CoPcS) catalyst for a refined Merox process of SMM oxidation for the preparation of DMDS was successfully synthesized by the chemical grafting method

Summary

Introduction

As an important fine chemical product, dimethyl disulfide (DMDS) is widely used as a soil fumigant [1,2,3], herbicide [4], food additive [5], sulfide hydrogenation catalyst, and chemical raw material [6]. The preparation method of DMDS is vital for all the chemical companies, which is commonly classified as four kinds of manufacturing processes: (1) the dimethyl sulfate process. (CH3 O) SO2 + Na2 S + S → CH3 SSCH3 + Na2 SO4 → catalyst. (Equation (1)) [7]; (2) the methanol vulcanization process (Equation (2)) [8,9]; (3) the methanethiol vulcanization process (Equation (3)) [10,11]; and (4) the methyl mercaptan oxidation process which is called Merox process (Equation (4)) [12]:

Methods

Results

Conclusion