This review article discusses the development of non-noble metal catalysts for the electrochemical hydrogen evolution reaction (HER). It emphasizes the nanostructuring of industrially relevant hydrotreating catalysts as potential HER electrocatalysts. The article highlights recent advances in the synthesis and nanostructuring of these catalysts, which may lead to more efficient catalysts for energy conversion. Hydrogen is a promising energy carrier due to its high energy density and clean combustion properties. However, current methods of hydrogen production rely on fossil fuels and emit CO₂. Electrolysis of water using renewable energy sources is a cleaner alternative, but efficient catalysts are needed to reduce overpotentials and improve reaction rates. Platinum group metals are the most efficient HER catalysts, but they are rare and expensive. Therefore, there is a need for alternative catalysts made from earth-abundant materials. The article reviews the mechanisms of HER, including the Volmer and Heyrovsky reactions, and discusses the factors that influence catalyst performance, such as the density and reactivity of active sites, electron transport, surface area, and stability. It also discusses the relationship between hydrotreating (HDT) and HER, noting that both processes involve hydrogen adsorption, but they differ in the nature of the reactions and the requirements for catalysts. The article then focuses on the nanostructuring of HDT catalysts for HER. It discusses the use of molybdenum disulfide (MoS₂) and tungsten disulfide (WS₂) as promising HER catalysts, highlighting their edge sites as active sites for HER. It also discusses the use of molybdenum carbides (Mo₂C) and tungsten carbides (Wx C) as HER catalysts, noting their platinum-like properties and their potential for efficient HER. The article also discusses the use of supported catalysts, such as carbon nanotubes and graphene, to improve the conductivity and dispersion of catalysts. The review concludes that nanostructuring of HDT catalysts can lead to more efficient HER catalysts, and that further research is needed to optimize these catalysts for practical applications. The article emphasizes the importance of understanding the fundamental mechanisms of HER and the role of catalyst structure in determining catalytic activity.This review article discusses the development of non-noble metal catalysts for the electrochemical hydrogen evolution reaction (HER). It emphasizes the nanostructuring of industrially relevant hydrotreating catalysts as potential HER electrocatalysts. The article highlights recent advances in the synthesis and nanostructuring of these catalysts, which may lead to more efficient catalysts for energy conversion. Hydrogen is a promising energy carrier due to its high energy density and clean combustion properties. However, current methods of hydrogen production rely on fossil fuels and emit CO₂. Electrolysis of water using renewable energy sources is a cleaner alternative, but efficient catalysts are needed to reduce overpotentials and improve reaction rates. Platinum group metals are the most efficient HER catalysts, but they are rare and expensive. Therefore, there is a need for alternative catalysts made from earth-abundant materials. The article reviews the mechanisms of HER, including the Volmer and Heyrovsky reactions, and discusses the factors that influence catalyst performance, such as the density and reactivity of active sites, electron transport, surface area, and stability. It also discusses the relationship between hydrotreating (HDT) and HER, noting that both processes involve hydrogen adsorption, but they differ in the nature of the reactions and the requirements for catalysts. The article then focuses on the nanostructuring of HDT catalysts for HER. It discusses the use of molybdenum disulfide (MoS₂) and tungsten disulfide (WS₂) as promising HER catalysts, highlighting their edge sites as active sites for HER. It also discusses the use of molybdenum carbides (Mo₂C) and tungsten carbides (Wx C) as HER catalysts, noting their platinum-like properties and their potential for efficient HER. The article also discusses the use of supported catalysts, such as carbon nanotubes and graphene, to improve the conductivity and dispersion of catalysts. The review concludes that nanostructuring of HDT catalysts can lead to more efficient HER catalysts, and that further research is needed to optimize these catalysts for practical applications. The article emphasizes the importance of understanding the fundamental mechanisms of HER and the role of catalyst structure in determining catalytic activity.