Understanding the Reactivity of Supported Late Transition Metals on a Bare Anatase (101) Surface: A Periodic Conceptual DFT Investigation

Geometrical Stabilities and Electronic Structures of Rh5 Nanoclusters on Rutile TiO2 (110) for Green Hydrogen Production

Addressing the urgent need for sustainable energy sources, this study investigates the intricate relationship between rhodium (Rh5) nanoclusters and TiO2 rutile (110) surfaces, aiming to advance photocatalytic water splitting for green hydrogen production. Motivated by the imperative to transition from conventional fossil fuels, this study employs density functional theory (DFT) with DFT-D3 and HSE06 hybrid functionals to analyse the geometrical stabilities and electronic structures of Rh5 nanoclusters on TiO2 rutile (110). TiO2, a prominent photocatalyst, faces challenges such as limited visible light absorption, leading researchers to explore noble metals like Rh as cocatalysts. Our results show that bipyramidal Rh5 nanoclusters exhibit enhanced stability and charge transfer when adsorbed on TiO2 rutile (110) compared to trapezoidal configurations. The most stable adsorption induces the oxidation of the nanocluster, altering the electronic structure of TiO2. Extending the analysis to defective TiO2 surfaces, this study explores the impact of Rh5 nanoclusters on oxygen vacancy formation, revealing the stabilisation of TiO2 and increased oxygen vacancy formation energy. This theoretical exploration contributes insights into the potential of Rh5 nanoclusters as efficient cocatalysts for TiO2-based photocatalytic systems, laying the foundation for experimental validations and the rational design of highly efficient photocatalysts for sustainable hydrogen production. The observed effects on electronic structures and oxygen vacancy formation emphasize the complex interactions between Rh5 nanoclusters and the TiO2 surface, guiding future research in the quest for clean energy alternatives.

Systematic Characterization of Electronic Metal-Support Interactions in Ceria-Supported Pt Particles

Electronic metal-support interactions affect the chemical and catalytic properties of metal particles supported on reducible metal oxides, but their characterization is challenging due to the complexity of the electronic structure of these systems. These interactions often involve different states with varying numbers and positions of strongly correlated d or f electrons and the corresponding polarons. In this work, we present an approach to characterize electronic metal-support interactions by means of computationally efficient density functional calculations within the projector augmented wave method. We describe Ce3+ cations with potentials that include a Ce4f electron in the frozen core, overcoming prevalent convergence and 4f electron localization issues. We systematically explore the stability and chemical properties of different electronic states for a Pt8/CeO2(111) model system, revealing the predominant effect of electronic metal-support interactions on Pt atoms located directly at the metal-oxide interface. Adsorption energies and the reactivity of these interface Pt atoms vary significantly upon donation of electrons to the oxide support, pointing to a strategy to selectively activate interfacial sites of metal particles supported on reducible metal oxides.