Abstract: Enzymes, or nature’s catalysts, are both reactive and selective thanks to their well-defined structures of which active components can cooperate effectively. Heterogenous catalysts, on the other hand, are often composed of a dominant binding site that limits their full reactivity potential. To shorten the gap between the two, one can mimic the former’s design and tailor the latter with multiple binding sites and reactive interfaces.

In this context, water-mediated CO oxidation over Au/TiO₂ provides a unique catalytic system for studying how the interplay of various sites can lead to exceptional reactivity. Together with detailed experimental characterizations, density functional theory (DFT) calculations identify surface water as a co-catalyst and provide mechanistic insights into the reaction. Inspired by this work, the prospect of multifunctional catalyst design is examined by probing CO oxidation over transition metal alloy surfaces by using a combination of DFT and microkinetic modeling. Our analysis indicates the possibility of creating highly reactive systems from much less active components and suggests general design rules for efficient catalyst screening.

These rules are incorporated into the formulation of improved palladium oxide catalysts for total methane oxidation, where strategic placements of surface promoters are shown to lead to increased activity. Finally, we attempt to leverage the biomimetic approach to design isolated, well-defined active sites supported on nanoporous materials such as metal organic frameworks. As a first step along this direction, a novel porphyrin-supported nanocluster system is proposed and computationally evaluated for selective oxidation of methane to methanol.