Near-surface environment control for selective catalysis
Abstract
One of the most important factors governing the efficiency of a reaction process is the selectivity to desired products. Achieving high selectivity is necessary in realizing efficient chemical processes that minimize energy inputs and waste but represents a major challenge for complex chemical feedstocks with multiple functional groups. Addressing this problem is important both in conventional production of chemicals and for the conversion of biomass to chemicals and fuels, requiring improved design of the materials that catalyze these reactions.
Our group has investigated several techniques for improving selectivity during the reactions of complex molecules, with a focus on manipulating the three-dimensional environment around the surface site. One approach is to modify catalyst surfaces with inorganic films of controlled composition and porosity to create confined spaces around the catalyst active sites. This approach presents several advantages, including chemical and thermal stability of the film, but has limitations in terms of being able to fine-tune the near-surface environment. An alternative approach involves the modification of the catalyst with organic monolayers. By changing the functional groups present within these layers, one can precisely control the near-surface environment to enhance specific reactant-surface interactions and thus improve catalyst performance. This presentation will address different ways in which surface functionalization can be used to improve reaction selectivity. These examples span various types of catalysts, including cases where the key reaction steps occur on metal surfaces, on metal oxide surfaces, and at interfaces between metals and metal oxides. The utility of the methods by which inorganic films or organic ligands can be used for selectivity control will be illustrated for reaction chemistries important in biomass refining, CO2 conversion, and the production of valuable chemicals.
