Sadan Syam, Svenum Ingeborg-Helene, Hanslin Sander Ø, Akola Jaakko
Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
SINTEF Industry, Postboks 4760 Torgarden, NO-7465 Trondheim, Norway.
Phys Chem Chem Phys. 2024 Oct 17;26(40):25957-25968. doi: 10.1039/d4cp02760d.
Nickel phosphides (NiP), particularly NiP, are promising catalysts for the acidic hydrogen evolution reaction (HER). Using density functional theory (DFT), we model HER at the potential of zero charge (PZC), incorporating solvation effects an explicit water cluster and implicit surrounding solvent. Comparing the Volmer, Tafel, and Heyrovsky steps under saturated hydrogen coverage on NiP(0001) terminations, we find that the NiP (pristine) surface termination prefers the Volmer-Volmer-Tafel (VVT) pathway with activation energy () of 0.57 eV. Conversely, the NiP + 4P (reconstructed) surface favors the Volmer-Heyrovsky (VH) pathway with = 0.60 eV. For the pristine surface termination, the differential gas-phase hydrogen adsorption free energies (Δ) correlate with the Volmer and Tafel step reaction energies, and a linear Bell-Evans-Polanyi relationship for the calculated activation and reaction energies validates the usefulness of the Δ descriptor for the Volmer step under PZC conditions. Nickel atoms play a crucial role in H production on both pristine and reconstructed surfaces, suggesting that modifications of the Ni sites can be used for catalyst design. Our findings highlight the importance of considering surface reconstruction and solvation effects on the HER catalytic performance.
磷化镍（NiP），特别是NiP，是用于酸性析氢反应（HER）的有前景的催化剂。使用密度泛函理论（DFT），我们在零电荷电位（PZC）下对HER进行建模，纳入了溶剂化效应——一个明确的水簇和隐含的周围溶剂。比较在NiP(0001)晶面上饱和氢覆盖下的伏尔默、塔菲尔和海洛夫斯基步骤，我们发现NiP（原始）表面晶面偏好伏尔默 - 伏尔默 - 塔菲尔（VVT）途径，活化能（）为0.57电子伏特。相反，NiP + 4P（重构）表面有利于伏尔默 - 海洛夫斯基（VH）途径， = 0.60电子伏特。对于原始表面晶面，微分气相氢吸附自由能（Δ）与伏尔默和塔菲尔步骤反应能量相关，并且计算的活化能和反应能量的线性贝尔 - 埃文斯 - 波拉尼关系验证了PZC条件下伏尔默步骤的Δ描述符的有用性。镍原子在原始和重构表面上的氢生成中都起着关键作用，这表明镍位点的修饰可用于催化剂设计。我们的发现突出了考虑表面重构和溶剂化效应对HER催化性能的重要性。
