Aromatics reduction over supported1 platinum catalysts. 3: Effects of catalyst precursors and pretreatment conditions on the performance of palladium-promoted platinum catalysts
- National Chung Cheng Univ., Chia-Yi (Taiwan, Province of China). Dept. of Chemical Engineering
- Chinese Petroleum Corp., Chia-Yi (Taiwan, Province of China)
Fast Fourier transformation infrared spectroscopy was used to characterize the formation of bimetallic interactions of {gamma}-Al{sub 2}O{sub 3}-supported Pd-Pt catalysts. The effects of bimetallic interactions on catalyst performance were examined in long-term stability tests, carried out with a pilot plant under the same operating conditions and feed as those of a commercial diesel hydrotreating process. These tests are the hydrotreating of straight run distillate diesel at 340 C, 580 psig, and H{sub 2}/oil (mol) = 2.5 over a 25 day period. The characterization results indicate that Pd precursors and pretreatment conditions affect Pd-Pt bimetallic interactions in the H{sub 2}-reduced catalysts and the catalyst performance. The Pd-Pt catalysts made from palladium(II) acetate without calcination pretreatment presented a significant Pd-Pt bimetallic interaction, as evidenced by a shift in the infrared absorption peak characteristic of terminal CO ligands adsorbed on the Pt clusters to higher energy, bridging CO on the Pd to lower energy, and a catalytic reduction of palladium(II) acetate by Pt. In contrast, no significant bimetallic interactions were observed for both catalysts made from palladium(II) acetate with a calcination at 450 C in air and from palladium amine. The long-term stability tests further indicate that the Pd-Pt catalysts with bimetallic interactions have a relatively high selectivity for aromatics reduction and hydrodenitrogenation (HDN), whereas they have a relatively low selectivity for hydrodesulfurization (HDS).
- OSTI ID:
- 404544
- Journal Information:
- Industrial and Engineering Chemistry Research, Vol. 35, Issue 11; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
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