Hou Liqiang, Li Zijian, Jang Haeseong, Kim Min Gyu, Cho Jaephil, Zhong Wenwu, Liu Shangguo, Liu Xien
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Department of Chemistry, City University of Hong Kong, Hong Kong, SAR, China.
Angew Chem Int Ed Engl. 2025 Mar 17;64(12):e202423756. doi: 10.1002/anie.202423756. Epub 2025 Jan 3.
To enhance the alkaline hydrogen evolution reaction (HER), it is crucial, yet challenging, to fundamentally understand and rationally modulate potential catalytic sites. In this study, we confirm that despite calculating a low water dissociation energy barrier and an appropriate H adsorption free energy (ΔG) at Ru-top sites, metallic Ru exhibits a relatively inferior activity for the alkaline HER. This is primarily because the Ru-top sites, which are potential H adsorption sites, are recessive catalytic sites, compared with the adjacent Ru-hollow sites that have a strong ΔG. To promote the transformation of Ru-top sites from recessive to dominant catalytic sites, interstitial Si atoms are implanted into the hollow sites. However, complete interstitial implantation leads to a high water dissociation energy barrier at the RuSi intermetallic surface. Thus, we present a partial interstitial incorporation strategy to form a Ru-RuSi heterostructure that not only converts the Ru-top sites from recessive to dominant catalytic sites but also preserves the low water dissociation energy barrier at the Ru surface. Moreover, the spontaneously formed built-in electric fields bidirectionally optimize the adsorption ability of the Ru sites, thereby greatly reducing the thermodynamic energy barrier and enhancing the alkaline HER.
为了增强碱性析氢反应（HER），从根本上理解并合理调控潜在的催化位点至关重要，但也具有挑战性。在本研究中，我们证实，尽管计算得出在Ru顶位具有较低的水解离能垒和合适的H吸附自由能（ΔG），但金属Ru对碱性HER表现出相对较差的活性。这主要是因为，与具有较强ΔG的相邻Ru中空位相比，作为潜在H吸附位点的Ru顶位是隐性催化位点。为了促进Ru顶位从隐性催化位点向显性催化位点的转变，将间隙Si原子注入到中空位中。然而，完全的间隙注入会导致RuSi金属间化合物表面具有较高的水解离能垒。因此，我们提出了一种部分间隙掺入策略，以形成Ru-RuSi异质结构，该结构不仅能将Ru顶位从隐性催化位点转变为显性催化位点，还能在Ru表面保留较低的水解离能垒。此外，自发形成的内建电场双向优化了Ru位点的吸附能力，从而极大地降低了热力学能垒并增强了碱性HER。
