Development and Evaluation of Ni–Cu–Pt\nMonolithic Catalysts for Improved Ethanol Autothermal Reforming and\nHydrogen Production

This study investigates\nthe development and characterization of\nNi-based catalytic monoliths for ethanol reforming, focusing on the\neffects of incorporating Cu and Pt as promoters. Al<sub>2</sub>O<sub>3</sub> monoliths were coated with α-Al<sub>2</sub>O<sub>3</sub> and impregnated with Ni, Cu, and Pt by using a wet impregnation\nmethod. The catalysts were characterized by field-emission scanning\nelectron microscopy (FESEM), energy-dispersive spectroscopy (EDS),\nX-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and\ntemperature-programmed reduction (TPR). The multitechnique characterization\nresults revealed differences between the monometallic Ni/α-Al<sub>2</sub>O<sub>3</sub> catalyst and the trimetallic Ni-Cu-Pt/α-Al<sub>2</sub>O<sub>3</sub> catalyst. A unique flower-like structure was\nidentified in the trimetallic catalyst, formed due to acid leaching\nduring the Pt impregnation step. The metal impregnation process did\nnot alter the crystalline structure of the Al<sub>2</sub>O<sub>3</sub> substrate with both catalysts primarily exhibiting oxide phases.\nThe Ni-Cu-Pt/α-Al<sub>2</sub>O<sub>3</sub> catalyst has surface\nconcentrations of Cu and Pt around 1.3% or lower, while Ni concentration\nexceeds 4.8%, confirming the presence of all three metals at the catalyst\nsurface, despite the acid leaching caused by the Pt impregnation.\nTPR analysis indicated complex metal-support interactions in the trimetallic\ncatalyst, with distinct reduction peaks compared with the monometallic\nNi/α-Al<sub>2</sub>O<sub>3</sub> catalyst. Catalytic evaluation\nrevealed that the trimetallic catalyst achieved similar ethanol conversion\nin comparison with the monometallic Ni/α-Al<sub>2</sub>O<sub>3</sub> catalyst but exhibited lower hydrogen selectivity due to\nreduced C–C bond breaking, likely influenced by the presence\nof Cu. These findings highlight the potential and challenges of using\ntrimetallic catalysts in ethanol reforming, with implications for\noptimizing catalyst composition and reaction conditions for hydrogen\nproduction.