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Supported metal (oxide) clusters, with both rich surface sites and high atom utilization efficiency, have shown improved activity and selectivity for many catalytic reactions over nanoparticle and single atom catalysts. Yet, the role of cluster catalysts has been rarely reported in CO2 electroreduction reaction (CO2RR), which is a promising route for converting CO2 to liquid fuels like formic acid with renewable electricity. Here we develop a bismuth oxide (BiOn) cluster catalyst for highly efficient CO2RR to formate. The BiOn cluster catalyst exhibits excellent activity, selectivity, and stability towards formate production, with a formate Faradaic efficiency of over 90% at a current density up to 500 mA·cm−2 in an alkaline membrane electrode assembly electrolyzer, corresponding to a mass activity as high as 3,750 A·gBi−1. The electrolyzer with the BiOn cluster catalyst delivers a remarkable formate production rate of 0.56 mmol·min−1 at a high single-pass CO2 conversion of 44%. Density functional theory calculations indicate that Bi4O3 cluster is more favorable for stabilizing the HCOO* intermediate than Bi(001) surface and single site BiC4 motif, rationalizing the improved formate production over the BiOn cluster catalyst. This work highlights the great importance of cluster catalysts in activity and selectivity control in electrocatalytic CO2 conversion. [ABSTRACT FROM AUTHOR]

Strain and support effects play a crucial role in heterogeneous catalysis, which has been intensively studied over metal-based catalysts. In contrast, there is little discussion about the two effects in oxide systems. In this work, using an ultrathin ZnO film as an example, we investigate strain and support effects on the structure and surface reactivity of oxide catalysts through density functional theory calculations. Our results suggest that tensile strain increases the surface reactivity of ZnO films as indicated by enhanced CO and NH3 adsorptions and compressive strain renders an early phase transition from an inert graphene-like phase to a more reactive wurtzite-like phase. The support (Au, Pt, and Ru) can promote the phase transition and surface reactivity concurrently, which exhibits a larger effect on the reactivity than the strain. The support effect can be ascribed to the increasing rumple and polarization of ZnO films through the strong ZnO–substrate interaction, which enhances the surface reactivity. The insight helps us to develop advanced oxide-based catalysts through the strain and/or substrate engineering. [ABSTRACT FROM AUTHOR]

Oxidative dehydrogenation of ethane (ODE) is limited by the facile deep oxidation and potential safety hazards. Now, electrochemical ODE reaction is incorporated into the anode of a solid oxide electrolysis cell, utilizing the oxygen species generated at anode to catalytically convert ethane. By infiltrating γ‐Al2O3 onto the surface of La0.6Sr0.4Co0.2Fe0.8O3‐δ‐Sm0.2Ce0.8O2‐δ (LSCF‐SDC) anode, the ethylene selectivity reaches as high as 92.5 %, while the highest ethane conversion is up to 29.1 % at 600 °C with optimized current and ethane flow rate. Density functional theory calculations and in situ X‐ray photoelectron spectroscopy characterizations reveal that the Al2O3/LSCF interfaces effectively reduce the amount of adsorbed oxygen species, leading to improved ethylene selectivity and stability, and that the formation of Al‐O‐Fe alters the electronic structure of interfacial Fe center with increased density of state around Fermi level and downshift of the empty band, which enhances ethane adsorption and conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • The initial reduction temperature of Cr oxides can be lowered by 70–160 K by the incorporation of 2.5 at.% Zn upon heating in ultrahigh vacuum. • Incorporation of Zn can change the reduction behaviors of CrO 2 -BL nanoislands. • Enhanced reducibility by introduction of Zn originates from the easier removal of lattice oxygen atoms due to Zn substitution. Mixed oxides play important roles in many heterogeneous catalytic processes, and understanding of interaction between different oxide components is crucial for synthesizing the catalysts with high performances. Here, we introduce trace of metallic Zn species into well-defined chromium oxide (Cr oxide) nanostructures grown on Au(1 1 1) including CrO 2 -bilayer nanoislands and Cr 2 O 7 dinuclear clusters and study the impact of the dopant on reducibility of the Cr oxides. Combining low-temperature scanning tunneling microscopy (LT-STM) and X-ray photoelectron spectroscopy (XPS), we demonstrate that incorporation of 2.5 at.% Zn can lower the initial reduction temperature of Cr oxides by 70–160 K upon heating in ultrahigh vacuum. The reduction degree of Zn-doped Cr oxide is much larger than the pure oxide at the same heating temperature. Density functional theory (DFT) calculations reveal that the enhanced reducibility of the pristine oxide via introduction of Zn dopant mainly comes from the promoted activity of oxygen atoms due to Zn substitution of surface Cr. [ABSTRACT FROM AUTHOR]