Dimethyl Terephthalate Hydrogenation to Dimethyl Cyclohexanedicarboxylates over Bimetallic Catalysts on Carbon Nanotubes

The synthesis and utilization of bimetallic catalysts for the hydrogenation of dimethyl terephthalate (DMT) to dimethyl cyclohexanedicarboxylates (DMCD) is described in this Article. A variety of techniques, such as low temperature N-2 adsorption-desorption, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and H-2 temperature-programmed desorption were employed to characterize both the supports and the catalysts. The influence of various operational parameters, for example reaction temperature, pressure, and time, on the catalytic performance for the hydrogenation of DMT was systematically analyzed. Under optimized conditions, a DMT conversion of 80% along with DMCD selectivity of 95% were achieved. Furthermore, efforts were also made to probe the catalyst stability. The enhanced catalytic performance of optimized Ru-Ni/CNT catalysts can be attributed to the tight immobilization of the metal particles on the carbon nanotubes and the unique properties of the nitric acid-treated carbon nanotubes.