Tetrahedral NiS2/NiSe2 heterocages with rich‐phase boundaries are synthesized through a simultaneous sulfuration/selenylation process using Ni‐based acetate hydroxide prisms as precursor. Such a nanocage‐like NiS2/NiSe2 heterostructure can expose more active sites, accelerate the mass transport of the ions/gas, and optimize the interfacial electronic structure, which shows a significantly lower overpotential of 290 mV at 20 mA cm−2 than those of NiS/NiS2 and NiSe2 as counterparts. The experimental characterizations and theoretical density functional theory (DFT) calculations unveil that the interfacial electron transfer from NiSe2 to NiS2 at the heterointerface can modulate the electronic structure of NiS2/NiSe2, which further cooperates synergistically to change the Gibbs free energy of oxygen‐containing intermediates as the rate‐determining step (RDS) from 2.16 eV (NiSe2) and 2.10 eV (NiS2) to 1.86 eV (NiS2/NiSe2 heterostructures) during the oxygen evolution reaction (OER) process. And as a result, tetrahedral NiS2/NiSe2 heterocages with dual‐phase synergy efficiently trigger the OER process, and accelerate the OER kinetics. This work provides insights into the roles of the interfacial electron transfer in electrocatalysis, and can be an admirable strategy to modulate the electronic structure for developing highly active electrocatalysts.
Direct conversion of syngas (CO/H 2 ) into higher alcohols is highly desirable but remains challenging due to the low C 2+ OH selectivity. Herein, an effective strategy was developed through the combination of partially reduced Zn-Cr-Al trinary oxides (ZnCrAlO x ) and Mo-based sulfides to significantly raise the alcohol selectivity. The introduction of K on Mo-based sulfides suppresses the acid sites and stabilizes alkoxy species (CH x O*), which greatly enhances the selectivity of alcohols. The close proximity of the two components on the multifunctional relay catalyst ZnCrAlO x |KNiMoS-MMO-5 can effectively promote the migration of reaction intermediates by shifting the DME formation equilibrium on ZnCrAlO x , achieving an alcohol selectivity of 60.4% with more than ∼72.7% of C 2+ OH selectivity in alcohols under a CO conversion of 9.8%, and significantly improves the turnover frequency (TOF) of C 2+ OH (71.9 h −1 ). A plausible reaction mechanism is also proposed on the multifunctional relay catalyst ZnCrAlO x |KNiMoS-MMO-5. This work provides a promising avenue to improve the selectivity of higher alcohols through a multifunctional relay catalyst affording multiple types of active sites.
The dual-phase synergy between CoP and MoO2 and the modulated electronic structure induced by heterointerfacial charge redistribution lead to enhanced H2O dissociation and optimized H-adsorption free energy, accelerating the HER in alkaline and acidic solutions.
Ultralong jagged PtMo–S nanowires with rich “interfacial active sites” were fabricated by using S as the “active auxiliary” to demonstrate the enhanced catalytic HER performance triggered by the electronic and synergistic effects of PtMo/MoSx.
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