This article presents a study on the use of platinum (Pt) single-atom and cluster catalysts for the hydrogen evolution reaction (HER) in water splitting. The research focuses on the synthesis of isolated Pt atoms and clusters using atomic layer deposition (ALD) on nitrogen-doped graphene nanosheets (NGNs). The study demonstrates that these Pt-based catalysts exhibit significantly enhanced catalytic activity and stability compared to commercial Pt/carbon catalysts. The Pt atoms and clusters on NGNs show a much higher HER activity, up to 37 times greater than the commercial Pt/C catalysts, due to the unique electronic structure of the Pt atoms on the nitrogen-doped graphene. The study also shows that the Pt atoms and clusters have a higher stability, as evidenced by long-term electrolysis tests and accelerated degradation tests. The results suggest that the strong interaction between the Pt atoms and the NGNs support is crucial for the stability and activity of the catalysts. The study also highlights the importance of controlling the size and distribution of the Pt catalysts on the NGNs to achieve optimal performance. The research provides a promising approach for the design of highly active and stable next-generation catalysts based on single Pt atoms and clusters, which have the potential to reduce the high cost of industrial commercial noble-metal catalysts.This article presents a study on the use of platinum (Pt) single-atom and cluster catalysts for the hydrogen evolution reaction (HER) in water splitting. The research focuses on the synthesis of isolated Pt atoms and clusters using atomic layer deposition (ALD) on nitrogen-doped graphene nanosheets (NGNs). The study demonstrates that these Pt-based catalysts exhibit significantly enhanced catalytic activity and stability compared to commercial Pt/carbon catalysts. The Pt atoms and clusters on NGNs show a much higher HER activity, up to 37 times greater than the commercial Pt/C catalysts, due to the unique electronic structure of the Pt atoms on the nitrogen-doped graphene. The study also shows that the Pt atoms and clusters have a higher stability, as evidenced by long-term electrolysis tests and accelerated degradation tests. The results suggest that the strong interaction between the Pt atoms and the NGNs support is crucial for the stability and activity of the catalysts. The study also highlights the importance of controlling the size and distribution of the Pt catalysts on the NGNs to achieve optimal performance. The research provides a promising approach for the design of highly active and stable next-generation catalysts based on single Pt atoms and clusters, which have the potential to reduce the high cost of industrial commercial noble-metal catalysts.