2 A cm^–2 Level Large-Scale Production of Hydrogen Enabled by Constructing Higher Capacity of Interface “Electron Pocket”

Abstract

The batch production of high-purity hydrogen is a key problem that restricts the progress of fuel cells and the blueprint for achieving carbon neutrality. Transition-metal chalcogenide heterojunctions exhibit certain activity toward electrochemical overall water splitting (EOWS), but their high-current-density catalytic performances are still unsatisfactory due to the slow kinetic progression (H* or *O → *OOH). Inspired by the “electron pocket” theory, we designed a Ni-Mo bimetallic disulfide interface heterojunction electrocatalyst system (NM-IHJ-V) with high electronic storage capacity around the Fermi level (−0.5 eV, +0.5 eV) (e-DFE), which injects more power into the kinetic progression processes of intermediate species in the EOWS process. Consequently, it achieves a superhigh current density of 2 A cm–2 level for EOWS (only 1.98 V voltage is needed), which is 11.23-fold higher than that of the benchmarked Pt/C//IrO2 (178 mA cm–2@1.98 V), as well as an excellent long-term stability of 200 h. Most strikingly, NM-IHJ-V can efficiently produce hydrogen at currents up to 5 A. Our proposed strategy of constructing catalysts to produce hydrogen at superhigh current density through the electron pocket theory will supply valuable insights for the designing other catalytic systems.

Epitaxial heterointerfacial electron bridge synchronizes oxygen evolution activity and stability on a layered double hydroxide surface

“…The degree of lattice matching between the catalyst and the support is an important factor that governs both the activity and stability of the catalyst. 41,43 Thus, to demonstrate the favorable regulation of the electron bridge Ni(OH) 2 on the heterojunction structure and the electron structure, density functional theory (DFT) calculations were conducted. The formation energy of FeCo-LDH on NFO and NF substrates was analyzed using the optimal configuration of LDH*/NFO and LDH/NF, respectively (Fig.…”

“…38,39 On the other hand, the “electron bridge” (electron density around the Fermi level [−0.5 eV, 0.5 eV], e-D EF ) of the catalyst can be also modulated by the underlying substrate to optimize the adsorption/desorption of the OER intermediates on the catalysts. 40–44 Currently, active LDH layers are introduced directly on the surface of nickel foam. 45–47 It has been noted that a high in-plane lattice mismatch (12.8%) exists between the cubic Ni(001) and typical facets of hexagonal/rhombic LDH.…”

Recent Progress in High‐Entropy Alloy Electrocatalysts for Hydrogen Evolution Reaction

“…Hence, significant research endeavors are directed toward the development of highly efficient and stable electrocatalysts for the effective production of hydrogen in acidic electrolytes. [123,124] In general, HER is a chemical process involving two electrons. However, when the electrolyte varies at different pH values, the electrode reaction processes also become more complex.…”