| Summary: | A series of Cu and Zn modified Ni/Al<sub>2</sub>O<sub>3</sub> catalysts were prepared using an incipient impregnation method for the selective hydrogenation of naphthalene into tetralin. X-ray diffraction (XRD), H<sub>2</sub>-Temperature programmed reduction (H<sub>2</sub>-TPR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were applied to reveal the structure regulation, and density functional theory (DFT) calculations were performed to investigate the electronic effect and reactant adsorptions on the active sites. The results showed that the addition of CuO promoted the hydrogenation of naphthalene with an inhibited tetraline selectivity. However, a simultaneously increasing naphthalene conversion and tetraline selectivity were achieved over the Zn modified Ni/Al<sub>2</sub>O<sub>3</sub> catalysts. The characterization and calculation results revealed that the doping of CuO improved the hydrogenation activity with a low tetralin selectivity due to the H spillover from the Cu. The addition of ZnO decreased the interaction between NiO<sub>x</sub> and Al<sub>2</sub>O<sub>3</sub> in NiZn/Al<sub>2</sub>O<sub>3</sub> catalysts, which efficiently increased the reduction ability of NiO<sub>x</sub> species and, thus, improved the naphthalene hydrogenation activity. The electron transfer from ZnO to NiO<sub>x</sub> weakened the adsorption of tetraline and resulted in increased tetraline selectivity. This work provides insight into developing efficient catalysts for heavy aromatics conversions via rational surface engineering.
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