Water Production Reaction on Rh(110)

In Situ Observation of Stepwise C-H Bond Scission: Deciphering the Catalytic Selectivity of Ethylbenzene-to-Styrene Conversion on TiO2

The conversion of light alkanes to olefins is crucial to the chemical industry. The quest for improved catalytic performance for this conversion is motivated by current drawbacks including: expensive noble metal catalysts, poor conversion, low selectivity, and fast decay of efficiency. The in situ visualization of complex catalysis at the atomic level is therefore a major advance in the rational framework upon building the future catalysts. Herein, the catalytic C-H bond activations of ethylbenzene on TiO₂(110)-(1 × 1) were explored with high-resolution scanning tunneling microscopy and first-principles calculations. We report that the first C-H bond scission is a two-step process that can be triggered by either heat or ultraviolet light at 80 K, with near 100% selectivity of β-CH bond cleavage. This work provides fundamental understanding of C-H bonds cleavage of ethylbenzene on metal oxides, and it may promote the design of new catalysts for selective styrene production under mild conditions.

Low-dimensional surface oxides in the oxidation of Rh particles

The oxidation of rhodium particles leads to the formation of low-dimensional nanostructures, namely ultrathin oxide films and stripes adsorbed on the metallic surface. These structures display unique electronic and structural properties, which have been studied in detail experimentally and theoretically in recent years. In this review, the state of research on low-dimensional surface oxides formed on Rh surfaces will be discussed with a special focus on the contributions derived from computational approaches. Several points elucidating the novel properties of the surface oxides will be addressed: (i) the structural relation between the surface oxides and their bulk counterparts, (ii) the electronic properties of the low-dimensional oxide films and (iii) potential catalytic and electronic applications of the surface oxides.

Atomic Structure and Bonding of Water Overlayer on Cu(110): The Borderline for Intact and Dissociative Adsorption

By carefully comparing the calculated and measured work function data, energetics, and vibrational spectroscopy, we determine explicitly the water structure in c(2 x 2) periodicity on Cu(110) to be an intact water overlayer with a majority component of H-down bilayer (95%) in low temperature experiments. Water dissociation is accessible by heating or ultraviolet illumination, resulting in a sensitive change in electron density at the surface and could therefore be monitored by work function measurement.