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The active sites for CO2 electroreduction (CO2R) to multi-carbon (C2+) products over oxide-derived copper (OD-Cu) catalysts are under long-term intense debate. This paper describes the atomic structure motifs for product-specific active sites on OD-Cu catalysts in CO2R. Herein, we describe realistic OD-Cu surface models by simulating the oxide-derived process via the molecular dynamic simulation with neural network (NN) potential. After the analysis of over 150 surface sites through NN potential based high-throughput testing, coupled with density functional theory calculations, three square-like sites for C–C coupling are identified. Among them, Σ3 grain boundary like planar-square sites and convex-square sites are responsible for ethylene production while step-square sites, i.e. n(111) × (100), favor alcohols generation, due to the geometric effect for stabilizing acetaldehyde intermediates and destabilizing Cu–O interactions, which are quantitatively demonstrated by combined theoretical and experimental results. This finding provides fundamental insights into the origin of activity and selectivity over Cu-based catalysts and illustrates the value of our research framework in identifying active sites for complex heterogeneous catalysts.

Titanium dioxide (TiO2) nanomaterials have garnered extensive scientific interest since 1972 and have been widely used in many areas, such as sustainable energy generation and the removal of environmental pollutants. Although TiO2 possesses the desired performance in utilizing ultraviolet light, its overall solar activity is still very limited because of a wide bandgap (3.0–3.2 eV) that cannot make use of visible light or light of longer wavelength. This phenomenon is a deficiency for TiO2 with respect to its potential application in visible light photocatalysis and photoelectrochemical devices, as well as photovoltaics and sensors. The high overpotential, sluggish migration, and rapid recombination of photogenerated electron/hole pairs are crucial factors that restrict further application of TiO2. Recently, a broad range of research efforts has been devoted to enhancing the optical and electrical properties of TiO2, resulting in improved photocatalytic activity. This review mainly outlines state-of-the-art modification strategies in optimizing the photocatalytic performance of TiO2, including the introduction of intrinsic defects and foreign species into the TiO2 lattice, morphology and crystal facet control, and the development of unique mesocrystal structures. The band structures, electronic properties, and chemical features of the modified TiO2 nanomaterials are clarified in detail along with details regarding their photocatalytic performance and various applications.

Metal oxides are widely employed in heterogeneous catalysis, but it remains challenging to determine their exact structure and understand the reaction mechanisms at the molecular level due to their structural complexity, in particular for binary oxides. This paper describes the observation of the strong electronic interaction between In 2 O 3 and monoclinic ZrO 2 (m-ZrO 2 ) by quasi-in-situ XPS experiments combined with theoretical studies, which leads to support-dependent methanol selectivity. In 2 O 3 /m-ZrO 2 exhibits methanol selectivity up to 84.6% with a CO 2 conversion of 12.1%. Moreover, at a wide range of temperatures, the methanol yield of In 2 O 3 /m-ZrO 2 is much higher than that of In 2 O 3 /t-ZrO 2 (t-: tetragonal), which is due to the high dispersion of the In−O−In structure over m-ZrO 2 as determined by in situ Raman spectra. The electron transfer from m-ZrO 2 to In 2 O 3 is confirmed by XPS and DFT calculations and improves the electron density of In 2 O 3 , which promotes H 2 dissociation and hydrogenation of formate intermediates to methanol. The concept of the electronic interaction between an oxide and a support provides guidelines to develop hydrogenation catalysts.

It is of great significance to reveal the detailed mechanism of neighboring effects between monomers, as they could not only affect the intermediate bonding but also change the reaction pathway. This paper describes the electronic effect between neighboring Zn/Co monomers effectively promoting CO2 electroreduction to CO. Zn and Co atoms coordinated on N doped carbon (ZnCoNC) show a CO faradaic efficiency of 93.2 % at −0.5 V versus RHE during a 30‐hours test. Extended X‐ray absorption fine structure measurements (EXAFS) indicated no direct metal–metal bonding and X‐ray absorption near‐edge structure (XANES) showed the electronic effect between Zn/Co monomers. In situ attenuated total reflection‐infrared spectroscopy (ATR‐IR) and density functional theory (DFT) calculations further revealed that the electronic effect between Zn/Co enhanced the *COOH intermediate bonding on Zn sites and thus promoted CO production. This work could act as a promising way to reveal the mechanism of neighboring monomers and to influence catalysis.

Pt single-atom catalysts are receiving more and more attention due to their different properties compared with nanostructures. As one typical kind of single-atom catalysts, Pt-based single-atom alloys (SAAs) have generated significant interest due to their application in several heterogeneous catalytic reactions. However, almost all of the reported Pt-based SAAs are on Cu surface. In addition, it is still great challenge to apply Pt single-atom alloys in electrocatalytic reactions. Herein, we demonstrated a fabrication of Pt/Pd SAA catalysts on nitrogen-doped carbon nanotubes by atomic layer deposition. The asprepared octahedral Pt/Pd SAA catalysts exhibited greatly improved activity compared to commercial Pt/C catalysts for electrochemical catalytic reactions. According to the X-ray adsorption spectrum, the Pt atoms in Pt/Pd SAA catalysts exhibited higher unoccupied 5d character density of states and a lower Pt−Pt coordination number, compared to those in core−shell structures. In addition, we used density functional theory calculation results to explain the enhanced mechanism of Pt/Pd SAA catalysts for electrochemical reactions. This study opens up an avenue of developing different types of Pt-based catalysts for electrocatalytic reactions and brings insight understanding about catalytic performances of SAA catalysts.

Metal nanoparticles encapsulated in zeolite have been recently developed as a special type of catalyst that shows significant advantages in activity, shape-selectivity, and stability over conventional supported catalysts. The selectivity modulation of encapsulated nanoparticle catalysis by the zeolite microenvironment is theoretically possible but not addressed yet. Here, we report the in situ encapsulation of sub-nanometric palladium species within MFI-type zeolites, which exhibit high activity and good stability in the hydroconversion of furfural as a model reaction of biomass upgrading. Remarkably, different products, e.g., furan, furfural alcohol, and 1,5-pentanediol, from furfural hydroconversion can be obtained when silicalite-1, Na-ZSM-5, and H-ZSM-5 are employed as hosts of palladium nanoparticles, respectively. Density functional theory calculations and spectroscopy investigations reveal that both the adsorption of furfural and the activation of hydrogen are significantly affected by the zeolite microenvironment, leading to different reaction pathways. Our work presents an elegant example of catalytic selectivity modulation of encapsulated metal nanoparticles by tuning the zeolite microenvironment.

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