Quantifying the lateral interactions between adspecies is necessary in the development of truly predictive, theoretical models for bimetallic catalysts, as they will significantly affect the coverage distribution of the adspecies and therefore the heterogeneous catalytic environment. To that end, we have characterized the benzene-benzene lateral interactions on a Pt (111) surface and a Pt3Sn (111) surface alloy. This coverage-dependent adsorption behavior was incorporated into a kinetic model for each surface and used to simulate the temperature-programmed desorption (TPD) spectra and the coverage dependence of the differential heat of adsorption [1]. We find that it is imperative to incorporate the effect of surface coverage in these theoretical models if the adsorption-desorption behavior is to be accurately predicted. We also find that the adsorption of benzene was significantly weaker on the Pt3Sn (111) than on Pt (111), and as such, we were able to assign the monolayer desorption of benzene to a TPD peak previously attributed entirely to multilayer benzene desorption [1]. While these ultra-high vacuum studies provide significant insight into the reactions occurring on the catalyst's surface under typical experimental conditions, liquid bio-oil has a high concentration of water which can significantly affect the surface species and reaction mechanisms [2,3]. In order to understand how water could affect the HDO mechanisms of phenol on Fe (110) and Ru(0001), we examined the influence of an aqueous environment on the HDO mechanism and the results show that the presence of water affects the elementary reactions involving the movement of hydrogen, promoting hydrogenation and tautomerization mechanisms. Furthermore, the presence of a hydroxyl species on the Fe (110) surface was found to be crucial in hydrogenating the aromatic ring with the surface hydroxyl acting as Brønsted acid sites [3].

Elucidating the function of each metal in a bimetallic single catalytic grain for hydrodeoxygenation reactions

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.