Systematic Investigation on Supported Gold Catalysts Prepared by Fluorine-Free Basic Etching Ti₃AlC₂ in Selective Oxidation of Aromatic Alcohols to Aldehydes

Conventional methods to prepare supported metal catalysts are chemical reduction and wet impregnation. This study developed and systematically investigated a novel reduction method based on simultaneous Ti₃AlC₂ fluorine-free etching and metal deposition to prepare gold catalysts. The new series of Au_pre/Ti₃Al_xC₂Ty catalysts were characterized by XRD, XPS, TEM, and SEM and were tested in the selective oxidation of representative aromatic alcohols to aldehydes. The catalytic results demonstrate the effectiveness of the preparation method and better catalytic performances of Au_pre/Ti₃Al_xC₂T_y, compared with those of catalysts prepared by traditional methods. Moreover, this work presents a comprehensive study on the influence of calcination in air, H₂, and Ar, and we found that the catalyst of Au_pre/Ti₃Al_xC₂T_y-Air600 obtained by calcination in air at 600 °C performed the best, owing to the synergistic effect between tiny surface TiO₂ species and Au NPs. The tests of reusability and hot filtration confirmed the catalyst stability.