▎ 摘　　要

NOVELTY - Co-N/CNT/Ti3C2Tx/rGO composite catalyst comprises Ti3C2Tx/rGO support, carbon nanotubes and Co-N compounds. USE - The Co-N/CNT/Ti3C2Tx/rGO composite catalyst is useful for potassium tetrahydroborate hydrogen production. ADVANTAGE - The composite catalyst: can inhibit agglomeration of metal nanoparticles and increase the active sites; N doping can act as an atomic barrier, which can significantly increase the surface area of cobalt catalysts by avoiding agglomeration, and N can also act as an electron donor to increase the electron density of cobalt, thereby further enhancing the catalytic activity of cobalt; open porous structure has good electrical conductivity, which is beneficial to the diffusion of aqueous solution and the timely desorption and release of generated hydrogen. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: Preparing Co-N/CNT/Ti3C2Tx/rGO composite catalyst, comprising (i) weighing Ti3C2Tx and GO powders and dissolving in deionized water respectively, sonicate for 2 hours under argon, collect the precipitate after centrifugation, freeze-drying, and placing the Ti3C2Tx and GO powders in tube furnace porcelain boat, in a hydrogen-argon mixed gas atmosphere, raising the temperature to 200°C at heating rate of 2°C/minute, kept for 1 hour, and then cooling to room temperature naturally to obtain Ti3C2Tx/rGO carrier, (ii) weighing the Ti3C2Tx/rGO carrier, dissolving in methanol, and ultrasonicating for 1-2 hours in an argon atmosphere to obtain a Ti3C2Tx/rGO suspension, (iii) weighing Co-N compound and dissolving in methanol, stirring and dispersing for 1 hour to obtain Co-N compound solution, dissolving 2-methylimidazole in methanol, add CNT and stir until it is completely dispersed to obtain 2-methylimidazole solution, (iv) adding Co-N compound solution to the Ti3C2Tx/rGO suspension, stirring for 1 hour, then quickly pour into 2-methylimidazole solution, stir under argon atmosphere for 7-8 hours, centrifuge with methanol, adding the suspension into watch glass and drying under vacuum at 70-80°C for 12-24 hours to obtain black-purple powder, and (v) heating the black-purple powder in step (iv) to 700-800°C at heating rate of 2-3°C/minute under hydrogen-argon mixed gas atmosphere, the temperature is kept for 2-5 hours to obtain the Co-N/CNT/Ti3C2Tx/rGO catalyst; and Use of Co-N/CNT/Ti3C2Tx/rGO composite catalyst in potassium tetrahydroborate hydrogen production, hydrogen production is catalytically produced in an aqueous solution with a potassium hydroxide concentration of 3% and a potassium tetrahydroborate concentration of 2-5%.