The hydrogen evolution reaction is one of the most studied processes in electrochemistry, and platinum is by far the best catalyst for this reaction. Despite the importance of this reaction on platinum, detailed and accurate kinetic measurements of the steps that lead to the main reaction are still lacking, particularly because of the fast rate of the reaction. Hydrogen adsorption on Pt(111) has been taken as a benchmark system in a large number of computational studies, but reliable experimental data to compare with the computational studies is very scarce. To gain further knowledge on this matter, a temperature study of the hydrogen adsorption reaction has been carried out to obtain kinetic information for this process on Pt(111) in alkaline solution. This was achieved by measuring electrochemical impedance spectra and cyclic voltammograms in the range of 278 ≤ ≤ 318 (K) to obtain the corresponding surface coverage by adsorbed species and the faradaic charge transfer resistance. From this data, the standard rate constant has been extracted with a kinetic model assuming a Frumkin-type isotherm, resulting in values of 2.60 × 10 ≤ ≤ 1.68 × 10 (s). The Arrehnius plot gives an activation energy of 32 kJ mol. Comparisons are made with values calculated by computational methods and reported values for the overall HER, giving a reference frame to support future studies on hydrogen catalysis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsami.0c13158 | DOI Listing |
ACS Nano
January 2025
Creative Research Initiative Center for Nanospace-confined Chemical Reactions (NCCR), Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea.
Unlike homogeneous metal complexes, achieving absolute control over reaction selectivity in heterogeneous catalysts remains a formidable challenge due to the unguided molecular adsorption/desorption on metal-surface sites. Conventional organic surface modifiers or ligands and rigid inorganic and metal-organic porous shells are not fully effective. Here, we introduce the concept of "ligand-porous shell cooperativity" to desirably reaction selectivity in heterogeneous catalysis.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China.
Long-range ordered high-entropy intermetallics (HEIs) were synthesized a thermodynamically-driven atomic ordering strategy. The (FeCoNi)(RuPt) HEI achieves 200 mA cm at an overpotential of 56 mV and a remarkable low Tafel slope of 50.4 mV dec in alkaline seawater.
View Article and Find Full Text PDFChemphyschem
January 2025
School of Energy and Power, New Energy, 02 Mengxi Street, 212003, Zhenjiang, CHINA.
Since hydrogen is a promising alternative to fossil fuels due to its high energy density and environmental friendliness, water electrolysis for hydrogen production has received widespread attentions wherein the development of active and stable catalytic materials is a key research direction. This article designs a dual transition metal doped functional graphene for hydrogen evolution reaction via density functional theory calculations. Among varied combinations, 16 candidates are screened out that are expected to be stable as reflected by the criterion of formation energy Ef < 0 and active due to its free energy of hydrogen adsorption ∆GH within the window of ±0.
View Article and Find Full Text PDFChem Sci
January 2025
Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University Suzhou Jiangsu 215123 China
Understanding the oxygen reduction reaction (ORR) mechanism and accurately characterizing the reaction interface are essential for improving fuel cell efficiency. We developed an active learning framework combining machine learning force fields and enhanced sampling to explore the dynamics and kinetics of the ORR on Fe-N/C using a fully explicit solvent model. Different possible reaction paths have been explored and the O adsorption process is confirmed as the rate-determining step of the ORR at the Fe-N/C-water interface, which needs to overcome a free energy barrier of 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Central South University, material science and engineering, 932 Lushan Road, 410083, Changsha, CHINA.
Hydrogen bond (HB) chemistry, a pivotal feature of aqueous zinc-ion batteries, modulates electrochemical processes through weak electrostatic interactions among water molecules. However, significant challenges persist, including sluggish desolvation kinetics and inescapable parasitic reactions at the electrolyte-electrode interface, associated with high water activity and strong Zn2+-solvent coordination. Herein, a targeted localized HB docking mechanism is activated by the polyhydroxy hexitol-based electrolyte, optimizing Zn2+ solvation structures via dipole interaction and reconstructing interfacial HB networks through preferential parallel adsorption.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!