Highly-efficient hydrogen production from ammonia decomposition over Co-doped graphdiyne under moderate temperature

[Display omitted] •Facile co-precipitation method yields efficient Co-doped graphdiyne catalysts.•Co-doped graphdiyne enhances NH3 decomposition (100% conversion at 550 ℃).•NHx dehydrogenation (x = 3) is the rate-determining step on Co-doped graphdiyne. Manufacturing hydrogen from ammonia decomposition is an efficient and promising approach for hydrogen utilization. However, its scalable application is significantly impeded by the requirements of precious metal ruthenium (Ru) as catalysts. Herein, we report a type of Co-doped graphdiyne catalyst for catalytically decomposing ammonia (NH3) to generate H2. The metal-doped graphdiyne catalysts were synthesized facilely using co-precipitation approach. The resultant composite catalysts significantly enhanced the reactivity and stability of ammonia decomposition. The Co-doped graphdiyne catalyst achieved nearly complete decomposition of ammonia at 550 ℃, and the conversion rate remained stable over 18 h of continuous reaction. The adsorption and decomposition of ammonia by Co-doped graphdiyne was studied by density functional theory (DFT) calculations. Nitrogen binding strength was used as a descriptor to elucidate the catalyst's activity and reaction kinetics, further supported by the reaction energy barrier. Our study highlights the tremendous potential of metal-doped graphdiyne catalysts for facile hydrogen production via NH3 decomposition, enabling safe and scalable hydrogen utilization.