Enhanced hydrodesulfurization activity of thiophene over hollow tubular CoMo unsupported catalysts

In this work, hollow tubular CoMo unsupported catalysts were prepared using cotton as a hard template with different Co and Mo molar ratios. The techniques, such as thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and low-temperature N2 adsorption-desorption were employed to characterize the physicochemical properties of the CoMo-x catalysts. The HDS activity evaluation results demonstrated that the thiophene conversion over the CoMo-3 catalyst was 95.82% at 1 MPa and 360 degrees C, which could be ascribed to the highly dispersed MoS2. Although the BET surface area of all catalysts was as low as 5-12 m2 g-1, the hollow tubular structure could enhance the diffusion of thiophene in the catalyst pore channel and elevate the exposure degree of MoS2. This study provides a new idea for using low-cost hard templates to prepare highly active unsupported HDS catalysts.