Lignite char supported nano-cobalt composite catalyst and preparation method thereof

A method for preparing a lignite char supported nano-cobalt composite catalyst, comprising the following steps:

• 1) crushing and screening original lignite blocks to obtain lignite particles;
• 2) adding a cobalt precursor and the lignite particles into a solvent and mixing, subjecting the lignite particles to an impregnating, and drying a resulting mixture after impregnating to obtain a solid substance A;
• and
• 3) subjecting the solid substance A to a high-temperature pyrolysis treatment to obtain the lignite char supported nano-cobalt composite catalyst;
• wherein
• adding the cobalt precursor and the lignite particles into a solvent and mixing, subjecting the lignite particles to the impregnating, and drying the resulting mixture after impregnating to obtain the solid substance A in step 2) comprises:
• adding the lignite particles to the solvent and ultrasonically dispersing, and then adding the cobalt precursor and continuing ultrasonically dispersing to form a mixed solution;
• stirring the mixed solution at a certain temperature until the solvent is fully volatilized, and drying remaining substance to obtain the solid substance A;
• and
• subjecting the solid substance A to a high-temperature pyrolysis treatment to obtain the lignite char supported nano-cobalt composite catalyst in step 3) comprises:
• heating the solid substance A to 700-900° C. at a heating rate of 0.5-10° C./min in an inert atmosphere, and holding for 1-6 h to obtain the lignite char supported nano-cobalt composite catalyst;
• wherein the lignite char supported nano-cobalt composite catalyst has a specific surface area of 350 m2/g-470 m2/g and a loading amount of nano-cobalt of 9 wt %-27 wt %.