连续合成N-(1-乙基丙基)-3,4-二甲基苯胺的催化剂及其性能研究

Catalyst preparation for continuous synthesis of N-(1-ethylpropyl)-3,4-dimethylaniline and its catalytic preformance

以3,4-二甲基硝基苯、3-戊酮和氢气为原料,通过自制自动化固定床反应器进行连续加氢和烷基化反应,探索N-(1-乙基丙基)-3,4-二甲基苯胺连续化生产的新工艺,系统考察Sn改性及活性组分铂前驱体对催化剂性能的影响,同时考察反应条件对原料转化率和产物选择性的影响。研究表明,Sn掺杂改性及通过使用氯铂酸钾作为活性组分前驱体可使PtSn/C催化剂活性增加,稳定性增强。在反应温度70℃、反应压力1.5 MPa和氢气原料物质的量比为10条件下,3,4-二甲基硝基苯转化率和N-(1-乙基丙基)-3,4-二甲基苯胺选择性最高,连续运行50 d产物收率均稳定在99%以上。本研究为绿色除草剂二甲戊灵的应用提供了技术支持。

In this paper,3,4-dimethylnitrobenzene,3-pentanone and hydrogen were used as raw materials to continuously carry out hydrogenation and alkylation reaction in self-made automatic fixed bed reactor,and a new process for continuous production of N-(1-ethylpropyl)-3,4-dimethylaniline was explored.The effects of Sn modification and active component platinum precursor on catalyst performance were systematically investigated.The effects of reaction conditions on the conversion of raw materials and the selectivity of products were also investigated.Studies have shown that Sn doping modification and the use of potassium chloroplatinate as the precursor of active component can increase the activity and stability of PtSn/C catalyst.The conversion of 3,4-dimethylnitrobenzene and selectivity of N-(1-ethylpropyl)-3,4-dimethylaniline were the highest when the reaction temperature was 70℃,the reaction pressure was 1.5 MPa and the molar ratio of hydrogen to material was 10.The product yield was stable above 99%after continuous operation for 50 days.This study provided technical support for the application of green herbicide dimepentaline.