Structure, Characterization and Reactivity of Pt–Sn Surface Alloys

Guidelines to Achieving High Selectivity for the Hydrogenation of α,β-Unsaturated Aldehydes with Bimetallic and Dilute Alloy Catalysts: A Review

“…The adsorption energetics of acrolein, crotonaldehyde, and prenal on SnPt(111) alloys have been investigated using surface science experiments ,, and DFT, ,,,− which showed weaker adsorption on the alloy compared to monometallic Pt(111). Furthermore, the decomposition of crotonaldehyde was reduced by 50% on SnPt(111) alloys compared to Pt(111), in agreement with reactor studies. , Upon increasing the Sn concentration from Pt 3 Sn­(111) to Pt 2 Sn­(111), the adsorption of crotonaldehyde was further weakened, and the decomposition products were not formed. Despite the lack of hydrogenation products, the observation is consistent with reactor studies that showed higher selectivity at higher Sn content.…”

“…Because the CC bond adsorption occurs via electron donation to the metal atoms, it is weakened when the electron density of the active metal increases. This decreases the probability of the CC bond reduction relative to that of the CO bond reduction, promoting the formation of the unsaturated alcohol. , In low pressure surface science experiments, the decomposition of the unsaturated aldehyde has predominated on reactive monometallic surfaces, such as Pt(111) and Pd(111), in the absence of H 2 . − ,− In contrast, such C–C bond breaking is tempered significantly on bimetallic surfaces due to the electronic modification of the surface. , …”

Designing Efficient Single-Atom Alloy Catalysts for Selective C═O Hydrogenation: A First-Principles, Active Learning and Microkinetic Study

“…More active metals, such as Ni, Pd, and Pt, exhibit stronger interactions with CC bonds, making them easier to activate. − This balance between reactivity and selectivity is a crucial factor in the catalyst design. Extensive research − has shown that the adsorption mode of the unsaturated aldehyde on the catalyst surface plays a pivotal role in the selectivity in the hydrogenation of unsaturated aldehydes. Various strategies have been employed to engineer the adsorption mode of the unsaturated aldehyde.…”

“…Various strategies have been employed to engineer the adsorption mode of the unsaturated aldehyde. (1) Utilizing confinement and steric effects: this strategy hinders the adsorption of the CC bond usually located in the middle of the molecule but favors the adsorption of the CO bond located at the terminal end of the molecule. − (2) Modulating the electronic structure of the active site: this strategy diminishes the adsorption of the CC bond as the electron density of the active metal increases. − (3) Designing targeted adsorption sites: this strategy enables specific adsorption of CO bonds. , Thereinto, the most straightforward and efficient approach is to design catalysts with tailored active sites for CO bond adsorption. Among all catalysts, single-atom alloy (SAA) stands out as a catalyst in which a small fraction of the active metal is precisely isolated on the surface of an inert metal host.…”