Surface Science Studies Relevant for Metal-catalyzed Biorefining Reactions
The objective of this contribution is to review mechanistic surface science studies aimed at elucidating the unique features of heterogeneous catalysis in biorefining processes. The main objective of surface science studies is generally to develop a detailed understanding of surface reaction mechanisms using spectroscopic (and, increasingly, computational) techniques. The rationale for such investigations, which are typically conducted on model surfaces under very low pressures, is that detailed structure-property relations will enable design of improved catalysts. We begin by discussing recent contributions made to the understanding of more traditional, vapor-phase chemical reactions that do not involve high oxygen functionality in the reacting species. A few examples are provided to illustrate the utility of surface reaction mechanism development in the design of improved catalysts. We then discuss some of the key reaction processes involved in biorefining operations to frame more specific questions related to heterogeneous catalysis. This is followed by a description of some of the major tools used in surface science investigations as well as the advantages and limitations of the surface science approach.