Optimizing Hydrogen Adsorption by d–d Orbital Modulation for Efficient Hydrogen Evolution Catalysis

Abstract

Unraveling the essence of hydrogen adsorption and desorption behaviors can fundamentally guide catalyst design and promote catalytic performance. Herein, the regulation of hydrogen adsorption is systematically investigated by d–d orbital interaction of metallic tungsten dioxide (WO2). Theoretical simulations show that the incorporation of post‐transition metal atoms including Fe, Co, Ni, and Cu can gradually reduce the bond order of W—M sites, consequently weakening the hydrogen adsorption and accelerating the hydrogen evolution reaction (HER) process. Under that theoretical guidance, various 3d metal doped WO2 electrocatalysts are systematically screened for HER catalysis. Among them, the Ni‐WO2/nickel foam exhibits an overpotential of 41 mV (−10 mA cm−2) and Tafel slope down to 47 mV dec−1 representing the best tungsten‐based HER catalysts so far. This work demonstrates that optimizing hydrogen adsorption via d–d orbital modulation is an effective approach to developing efficient and robust catalysts.

d–sp orbital hybridization: a strategy for activity improvement of transition metal catalysts

“…With the help of theoretical simulations, Liu et al proposed that d-d orbital hybridization between the W and M (M = Fe, Co, Ni, and Cu) can not only weaken the hydrogen adsorption on the WO 2 surface, but also accelerate the HER process. 58 They also successfully synthesized a series of 3d metal doped WO 2 electrocatalysts for the HER. Among them, the Ni-WO 2 /nickel foam possesses excellent catalytic activity.…”

CoW Bimetallic Carbide Nanocatalysts: Computational Exploration, Confined Disassembly–Assembly Synthesis and Alkaline/Seawater Hydrogen Evolution

“…Such an electron transfer can effectively increase the occupancy of the d-orbitals of the Co catalyst, leading to the much weakened metal-H bonding, as well as the optimized H adsorption Gibbs free energy. [20,47] XPS measurements of Co 6 W 6 C catalysts of varied W/Co ratios were conducted to further study the concentration-dependent electron distributions. The W 4f spectra present four peaks as illustrated in Figure 3d, in which the Co 6 W 6 C-2-600 possesses the most negative charging of W atom among all Co 6 W 6 C-600 catalysts, which show a negative shift up to ≈0.25 eV.…”

Engineering 3d–2p–4f Gradient Orbital Coupling to Enhance Electrocatalytic Oxygen Reduction

“…[24] Liu et al demonstrated the introduction of 3d-metal such as Fe, Co, Ni, and Cu into WO 2 regulates the orbital hybridization between metal 3d states and W 5d states, thus optimizing the coordination strength of *H during the hydrogen evolution reaction. [21] Additionally, by incorporating the p-block such as S anions into the subshell of Ru-N 4 -C, the enhanced ORR activity was obtained in terms of the downshifted Ru d-band, which was ascribed to the S-anion-induced d-p interaction. [25] Despite the abundant research on d-d and d-p orbital coupling in tuning electrocatalytic activity, still few works converge on 3d-4f orbital coupling because 4f orbitals The development of highly efficient and economical materials for the oxygen reduction reaction (ORR) plays a key role in practical energy conversion technologies.…”

“…The electronic structure of 3d/4d metals can be modulated by other d-block metals owing to the extended electronic wave function of post-periodical d orbitals, which provides the large possibility of spin-orbit coupling in activating triplet-state O 2 molecules. [21][22][23] For example, the Mo 2 C coupled with Pd in atomic layers exhibited highly ORR activity due to the optimized d band center from strong metalsupport interactions. [24] Liu et al demonstrated the introduction of 3d-metal such as Fe, Co, Ni, and Cu into WO 2 regulates the orbital hybridization between metal 3d states and W 5d states, thus optimizing the coordination strength of *H during the hydrogen evolution reaction.…”