Abstract:
Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanocomposite (bentonite) surface using a microwave-assisted solvothermal method. The catalyst particles were examined by TEM and X-ray diffraction. The palladium immobilized on the bentonite crystal surface was identified using an XRD and HRTEM device. The obtained catalyst possesses the advantageous property of being easily separable due to its magnetizability on a natural mineral support largely available and obtained through low carbon- and energy footprint methods. The catalyst demonstrated outstanding performance with a 2,4-DNT conversion rate exceeding 99% along with high yields and selectivity towards 2,4-TDA and all of this achieved within a short reaction time. Furthermore, the developed catalyst exhibited excellent stability, attributed to the strong interaction between the catalytically active metal and its support. Even after four cycles of reuse, the catalytic activity remained unaffected and the Pd content of the catalyst did not change, which indicates that the palladium component remained firmly attached to the magnetic support\'s surface.
摘要:
甲苯二胺(TDA)是聚氨酯工业的主要原料,它的生产非常重要。TDA通过2,4-二硝基甲苯(2,4-DNT)的催化氢化获得。在这项研究中,通过使用微波辅助溶剂热法将钴铁氧体纳米颗粒分解到天然粘土-氧化物纳米复合材料(膨润土)表面上,开发了一种特殊的加氢催化剂。通过TEM和X射线衍射检查催化剂颗粒。使用XRD和HRTEM装置鉴定固定在膨润土晶体表面上的钯。所获得的催化剂具有易于分离的有利性质,这是由于其在天然矿物载体上的可磁化性,该载体可大量获得并通过低碳和能量足迹方法获得。该催化剂表现出优异的性能,2,4-DNT转化率超过99%,以及对2,4-TDA的高收率和选择性,并且所有这些在短反应时间内实现。此外,所开发的催化剂表现出优异的稳定性,归因于催化活性金属与其载体之间的强相互作用。即使经过四个循环的重复使用,催化活性保持不受影响,催化剂的Pd含量没有变化,这表明钯组分仍然牢固地附着在磁性载体的表面。