Dehydrogenation of methylcyclohexane over layered bimetallic hydroxide-derived Pt/Co-Al-O catalysts

In this paper, petal sheet layered Co-Al bimetallic hydroxides were prepared using the hydrothermal method using methanol as a solvent. Pt/Co-Al-O catalysts were produced after the impregnation method and H 2 reduction. This catalyst was applied to the dehydrogenation reaction process of methylcyclohexane to toluene. A fixed-bed reaction device carried out comparative tests of this series of catalysts, and the effect of Co addition on the performance of Pt/Co-Al-O catalysts was investigated in detail. Among them, the Pt/Co 3 -Al 1 -O catalyst showed the best performance with high toluene selectivity throughout the dehydrogenation process. The MCH conversion started to be greater than 90% at 330 °C, and the hydrogenolysis rate was 262.7 mmol/g Pt /min. The conversion gradually increased with the reaction temperature, and the conversion could reach 99.5% at 410 °C. The appropriate introduction of Co element can reduce the excessive strong acidic sites of Al 2 O 3 itself and retain a certain number of weak acidic sites, while the bimetallic hydroxide carrier improves the dispersibility of the active component, reduces its particle size, and forms a certain strong interaction between the carrier and Pt. The final conversion of the catalyst decreased by about 2% in the 100 h stability test at 380 °C, which indicated that the Pt/Co 3 –Al 1 –O catalyst had strong coking resistance and good stability. These results indicate that the Pt/Co–Al–O series catalysts have potential industrial applications in hydrogen energy utilization. • First application of Co–Al bimetallic hydroxide carriers as MCH dehydrogenation catalysts. • Preparation of Co–Al-LDH with special morphology to promote dehydrogenation reaction. • Prepared Pt/Co–Al–O catalysts and compared the effects of the ratio of Co and Al on the performance of the catalysts.