# Noble Metal-Based Heterogeneous Catalysts for Electrochemical Hydrogen Evolution Reaction
###### Abstract  
Hydrogen energy, a green renewable energy, has shown great potential in developing new energy and alleviating environmental problems. Water electrolysis is an effective method to achieve large-scale clean hydrogen production, but this process needs to consume a huge amount of electric energy. It is urgent to develop high-activity, high-stability and low-cost catalysts to reduce the consumption of electric energy. At present, the noble metal catalyst is the star material in the hydrogen evolution reaction (HER), but its stability and high cost restrict its large-scale application. In this review, we comprehensively discussed the research progress on noble metal-based heterogeneous electrocatalysts used in water electrolysis for hydrogen production. Firstly, we analyzed the influence factors for hydrogen production performance, including the mass transfer process, the adsorption-desorption process, the catalytic process, and the influence of the working electrode and electrolyte. Then, we discussed the relationship between catalytic activity and electronic structure and chemical composition in view of theoretical calculations and summarized the strategies for developing efficient catalysts (alloying and interface engineering). Finally, we highlighted the challenges for the practical application of noble metal-based hydrogen evolution electrocatalysts. p _applied_  
_sciences_  
Footnote †: Footnote †:  
+++ ==WARNING: Truncated because of repetitions==
: thanks: [  
Footnote †: nature, the cost of hydrogen production will be greatly reduced by combining photovoltaic and wind power generation and triboelectric nanogenerator (TENG) using ocean energy with water electrolytic equipment [6,7]. Therefore, it is necessary to develop high-efficient electrocatalysts and new electricity sources to overcome the overpotential and improve the energy conversion efficiency of electric energy to chemical energy. At present, noble metal-based materials are the most efficient catalysts for the HER (Hydrogen Evolution Reaction), because their \(\Delta\)G\({}_{\text{H}^{*}}\) is close to zero, which is the most optimized hydrogen adsorption free energy [8]. However, their practicability is greatly reduced due to the high price and insufficient reserves of precious metals, as well as the dissolution, agglomeration and poisoning in the electrocatalytic process [9]. One of the major challenges of noble metal catalysis is to improve the utilization efficiency, stability and durability of the noble metal atoms without reducing catalyst activity. Therefore, researchers adopted a variety of strategies to design and synthesize noble metal-based catalysts, such as heteroatom doping, alloying, interface engineering, and introducing defects. In addition, many factors including the particle size, shape and metal-support interfaces can have significant influences on the catalytic properties of noble metal catalysts [10]. Meanwhile, some noble metal catalysts with different morphology and structures, such as a variety of hollow structures [11] and even single atom catalysts [12,13], were designed to achieve the goal of hydrogen economy using efficient hydrogen production. In addition, optimizing the electrode preparation method and selecting the appropriate electrolyte can also maximize the use of the catalyst during the electrolytic process, further improving the efficiency of hydrogen production [14,15,16]. In this review, we first summarize several factors affecting the HER electrocatalytic performance, including the mass transfer process, adsorption-desorption process, catalytic process and the influence of electrodes and electrolytes. Then, we introduce the catalytic mechanism of catalyst promoting hydrogen evolution. The research progress of noble metal-based materials in the electrocatalytic HER field is also summarized, mainly focusing on the structure of catalysts, including alloying and interface engineering.