Performance of carbon-modified Pd/SBA-15 catalyst for 2-ethylanthraquinone hydrogenation

Silica SBA-15 without removal of template P123 was calcined in an inert atmosphere and the carbon-modified SBA-15 thus obtained was used as the support of Pd catalyst for the hydrogenation of 2-ethylanthraquinone (EAQ). The effects of extraction times of P123 in SBA-15 with water prior to inert calcination and calcination temperature on the structure and catalytic performance of Pd catalyst were studied. The results of elemental analysis, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma, Fourier transform infrared spectroscopy, Raman spectra, water contact angle measurement, N-2 adsorption-desorption, transmission electron microscopy and energy dispersive X-ray mapping showed that carbon content of catalysts varied in the range of 3.4 % and 1.1 % with increasing extraction times from 0 to 6 due to the decrease in the residual amount of P123 in uncalcined SBA-15. With rising calcination temperature, the occurrence state of carbon in catalysts was converted from amorphism into graphite. The Pd catalyst supported on SBA-15 extracted for 3 times and calcined at 650 degrees C had 2.0 % carbon, and exhibited the highest activity (0.37 molH(2)center dot gPd(-1).min(-1)) and selectivity (98.9 %). This is due to the presence of appropriate amount of carbon, which provided a relatively high hydrophobicity without significantly reducing the specific surface area and pore size of SBA-15 support. The high hydrophobicity benefits the adsorption of EAQ from the working solution to the surface of catalyst.

Automated summary

The study investigated the effects of carbon content on the structure and catalytic activity of Pd catalyst supported on SBA-15 for hydrogenation of 2-ethylanthraquinone. It was found that an appropriate amount of carbon led to higher activity and selectivity. Pd catalyst supported on SBA-15 extracted three times and calcined at 650 degrees Celsius showed the best performance.