Asymmetric Exchange Interaction Induces Highly Efficient Alkaline Hydrogen Evolution in RhFe Bimetallene

Abstract

An RhFe bimetallene with Fe atoms doped into Rh host for efficient hydrogen evolution reaction (HER), is constructed. When two doped Fe atoms occupy neighboring asymmetric spatial positions, their asymmetric exchange interaction drives electron hopping between the dxy orbital of a Fe atom and the dz2 orbital of its neighboring Fe atom to push the d band center closer to the Fermi level as a result of electronic state reconstruction. The designed bimetallene with thickness of 0.77 nm (5 atomic layers), possesses excellent HER performance. The low overpotentials of 24.4 and 34.6 mV are achieved at the 10 and 100 mA cm−2 current densities in 1 m KOH solution, respectively. An ultra‐low Tafel slope of 8.9 mV dec−1 shows that this kind of RhFe bimetallene is of an ultrafast kinetic process. This work provides a strategy for designing HER catalysts with double metal composites.

The Co d-band center modulation of LaCoO3−δfor improved peroxymonosulfate activation

“…The energy difference (Δ) between d xy (d yz ) and d xz in P-LCO is 0.12 eV, which is larger than that in LCO (0.08 eV), indicating that more structural distortion was generated after P doping. 37,38…”

“…The energy difference (Δ) between d xy (d yz ) and d xz in P-LCO is 0.12 eV, which is larger than that in LCO (0.08 eV), indicating that more structural distortion was generated after P doping. 37,38 The surface alkalinity, acidity, and redox ability of LCO and LC 0.8 P 0.2 O are investigated by CO 2 -TPD, NH 3 -TPD, and H 2 -TPR, respectively (Fig. 4).…”

Molybdenum Oxycarbide Supported Rh‐Clusters with Modulated Interstitial C–O Microenvironments for Promoting Hydrogen Evolution

“…Benefiting from the unique electronic configuration (Figure 5b), the Rh/MoOC catalyst only needs the minimum energy barriers (0.48 eV) for the H 2 O dissociation, which is significantly lower than that of Rh/MoO 2 (1.14 eV) and Rh/Mo 2 C (0.93 eV) (Figure 5g). Moreover, the most optimal H* adsorption with a Δ G H* value of 0.004 eV is obtained for Rh/MoOC, [ 48,49 ] while the Rh/MoO 2 and Rh/Mo 2 C exhibit a more negative Δ G H* value of −0.040 and −0.190 eV, respectively, (Figure 5h). The above analyses prove that the unique electron‐deficient configuration of Rh and O sites in MoOC support can optimize the adsorption energy of both H 2 O and its intermediates, thus enhancing the intrinsic catalytic hydrogen‐evolving activities.…”

Design and Performance of Rh Nanocatalysts for Boosted H2 Generation in Alkaline Media

“…Meanwhile, doping a Rh substrate cannot generate a new phase due to the low quantity of the added foreign element. In this context, the doping of a Rh catalyst with other metallic elements (e.g., Co, Fe, Mn, and Cr) led to local electron redistribution, lattice distortions, and low coordination numbers of active sites, which were beneficial for the promotion toward the alkaline HER. − Our DFT calculations confirmed that the HER performance of the Co-doped Rh nanoparticles was dependent on the doping effect . These Co-doped Rh nanoparticles featured an ultrasmall size (<2 nm) and were highly dispersed on carbon black (Figure a).…”