| AVS 63rd International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Thursday Sessions |
| Session HC+SS-ThM |
| Session: | Dynamics of Gas-surface Interactions in Heterogeneous Catalysis |
| Presenter: | Dominic Esan, University of Illinois at Chicago |
| Authors: | D.A. Esan, University of Illinois at Chicago Y.D. Ren, University of Illinois at Chicago I.B. Waluyo, Brookhaven National Laboratory M. Trenary, University of Illinois at Chicago |
| Correspondent: | Click to Email |
The partial hydrogenation of α, β-unsaturated aldehyde s is an important step in several synthetic industrial processes especially in the fine chemicals and pharmaceutical industries. Generally, it has been established that the thermodynamics of the catalytic hydrogenation of these unsaturated aldehydes favor the formation of saturated aldehydes via the hydrogenation of the C=C bond while the manipulation of the kinetics of the process may yield the desired unsaturated alcohol product via the hydrogenation of the C=O bond. Most of the studies done on single metal surfaces using acrolein (CH2=CH=CHO), the smallest of these aldehydes, show that the thermodynamically-preferred product (propanal) is always the favored product. However, bimetallic systems have been shown to possess unique properties, compared to their single metal counterparts, including novel reaction pathways. Thus, our aim is to study acrolein hydrogenation on a bimetallic Pt/Ru(001) system to determine if the presence of the Pt atoms can enhance the selectivity and activity towards the formation of the unsaturated alcohol (2-propenol).
In this initial study, temperature programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS) were used to determine if the bare Ru(001) surface is active towards (partial and complete) hydrogenation of acrolein and if it’s selective for the desired product (2-propenol). At low coverages, acrolein was found to adsorb on the surface, at 90 K, via the C=O bond and completely decomposes to CO(g) around 460 K. As the coverage increases, adsorption via the C=C bond predominates and most of the acrolein desorbs molecularly or decomposes to CO(g). However, some of the acrolein also self-hydrogenates to yield all the possible hydrogenation products – propanal, 2-propenol, and 1-propanol with TPD peak temperatures at 180, 210, and 280 K respectively – with propanal having the highest yield. Co-adsorption with H2(g) enhances the adsorption via the C=C bond and the yield of all the products. These results will serve as a guide for the study on the Pt/Ru(001) system.