Reversible transformation between terrace and step sites of Pt nanoparticles on titanium under CO and O2 environments

CO2-Assisted Dehydrogenation of Propane by Atomically Dispersed Pt on MXenes

“…The effects of morphologies of metallic Pt on its activity, selectivity, and durability have been previously studied, where the terrace and step sites were distinguished as sites for coke deposition due to their nonselective cleavage of C–H and C–C bonds. − , Recent studies further evidenced that adjacent multi-Pt sites favored the deep dehydrogenation of propylene, leading to coke deposition, while the Pt SA sites favored only the propane dehydrogenation to propylene, significantly improving the selectivity and stability. − The stability of SA anchored on the support is one of the major concerns for single atom catalysts, where migration of adatoms driven by differences in free energy via Ostwald ripening can lead to aggregation of Pt SAs, thus aggravating coke deposition. Here, the antisintering ability of the Pt SA anchored at the O vacancy of MXene, namely the Pt 1 @MXenes (Figure S1), was first assessed by the chemical-potential-based thermodynamic model developed by Liu et al The surface of the Pt NP is assumed to be mainly composed of the (111) and (100) facets, and the surface energies were calculated to be 1.56 J/m 2 for Pt(111) and 1.87 J/m 2 for Pt(100).…”

“…The effects of morphologies of metallic Pt on its activity, selectivity, and durability have been previously studied, where the terrace and step sites 87 were distinguished as sites for coke deposition due to their nonselective cleavage of C−H and C−C bonds. [7][8][9]88 Recent studies further evidenced that adjacent multi-Pt sites favored the deep dehydrogenation of propylene, leading to coke deposition, while the Pt SA sites favored only the propane dehydrogenation to propylene, significantly improving the selectivity and stability.…”

Hydrogen, Ammonia and Symbiotic/Smart Fertilizer Production Using Renewable Feedstock and CO2 Utilization through Catalytic Processes and Nonthermal Plasma with Novel Catalysts and In Situ Reactive Separation: A Roadmap for Sustainable and Innovation-Based Technology

“…The central electrode platform is secured by screws (302). Water spray at the top (305) and bottom (303) facility is provided in which spray water is fed through a concentric pipe system (307,308) while syngas is fed (304) or collected (306) from the annular regions. Tar captured on the porous catalytic earth electrode and in the tar collection space (316) both act as a barrier for the gas and hence tar removal from the bottom exit (317) has to be carried out gradually.…”

“…In situ spectroscopic techniques were developed for the detection of reaction intermediates [302,303] and reaction-environment-dependent dynamic evolution of active sites in the catalyst (i.e., the transformation between the surface terrace and step sites) [304]. Atomically resolved mapping of catalyst surfaces was achieved using High Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM) [280,305,306], Atomic Force Microscopy (AFM), Scanning Tunnelling Microscopy (STM) or combined AFM and STM have been successfully used for the in situ observation of oxygen vacancy sites and their generation [307][308][309][310][311][312].…”