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Single-atom catalysts (SACs) in heterogeneous catalysts have attracted increasing attention and the adsorption and nucleation of single atom on the surface are closely related to the performance of the catalyst. The present work employed density functional theory calculations to examine the adsorption of single Au atom and nucleation on γ-Al2O3 surfaces at the atomic level. The effect of surface hydroxyls group on the adsorption and nucleation of single Au atom on γ-Al2O3 surfaces is explored. It was found that the spillover reactions of surface hydroxyls H atoms with the deposited Au− are not available on the hydroxylated surface. The interaction of Au to the clean surface is the stronger than to the hydroxylated surface. The even–odd alternations of Aux and weak binding of single Au atoms to γ-Al2O3 leads to large even-numbered Au cluster on the surface. Density of states and electron density difference analysis show that the electronic structure of Au/γ-Al2O3 is quite different from the reported Cu and Pd on Al2O3. [ABSTRACT FROM AUTHOR]

Rational design of highly active transition-metal phosphides for electrocatalyzing overall water splitting in a wide pH range assisted by first-principle calculations can efficiently save the developing cost and hence is quite attractive. Under the guidance of density-functional theory (DFT) calculations that the introduction of dopants (Fe, Mn, and Ni) into CoP could promote the hydrogen evolution reaction (HER) performances, a series of binder-free CoMxP/carbon cloth (CC; M = Fe, Mn, and Ni; x = 0, 0.05, 0.2, 0.5, and 1) were fabricated. Both experimental measurements and DFT calculations confirm the electronic modulation of dopants. DFT calculations further reveal that the modulated electronic structure promotes the electronic conductivity, favors the adsorption of key species, and consequently promotes the electrochemical performances. As predicted, the bimetallic phosphides demonstrate excellent HER performances in alkaline, acidic, and alkaline simulated seawater solutions and also deliver excellent oxygen evolution reaction (OER) performances, overwhelming the commercial RuO2. Benefiting from the modulated electronic structure and the hierarchical structure with massive CoFe0.05P zero-dimensional (0D) quantum dots anchored on two-dimensional (2D) N-doped porous carbon, CoFe0.05P delivered the best HER in four kinds of electrolytes (η10 of 73 mV in an alkaline simulated seawater solution) and OER in two kinds of electrolytes (η10 of 264 mV in an alkaline solution) with excellent stability of 45 h in the alkaline solution. The assembled CoFe0.05P/CC//CoFe0.05P/CC with the electrodes folded by 180° can still maintain a low cell potential of 1.62 V at 10 mA·cm−2. This work proves the feasibility of the reported rational design strategy of developing efficient electrocatalysts for overall water splitting in a wide pH range. [ABSTRACT FROM AUTHOR]